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  <xsd:element abstract="true" id="ofc_NotesReceivableFromCityOfHuntsvilleMember" name="NotesReceivableFromCityOfHuntsvilleMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="ofc_Number15And45WestGudeDriveMember" name="Number15And45WestGudeDriveMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfOperatingPropertiesClassifiedAsHeldForSale" name="NumberOfOperatingPropertiesClassifiedAsHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu" name="NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfPrimaryOfficePropertySegments" name="NumberOfPrimaryOfficePropertySegments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_NumberOfPropertiesComprisingProjectIncludedInDisposition" name="NumberOfPropertiesComprisingProjectIncludedInDisposition" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_NumberOfPropertiesSold" name="NumberOfPropertiesSold" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfRealEstateOperatingPropertiesSold" name="NumberOfRealEstateOperatingPropertiesSold" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_NumberOfRealEstatePropertiesPlacedInService" name="NumberOfRealEstatePropertiesPlacedInService" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfRealEstatePropertiesSold" name="NumberOfRealEstatePropertiesSold" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfSeriesLPreferredUnitsOfOperatingPartnershipReceivedInExchangeForOfferingProceeds" name="NumberOfSeriesLPreferredUnitsOfOperatingPartnershipReceivedInExchangeForOfferingProceeds" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfTrusteesControllingAdditionalCommonUnits" name="NumberOfTrusteesControllingAdditionalCommonUnits" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OfferingByTypeAxis" name="OfferingByTypeAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OfferingByTypeDomain" name="OfferingByTypeDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OfficePropertiesUnderConstructionOrRedevelopmentMember" name="OfficePropertiesUnderConstructionOrRedevelopmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OperatingNotesReceivableAbstract" name="OperatingNotesReceivableAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_OperatingNotesReceivableLongTerm" name="OperatingNotesReceivableLongTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_OperatingOfficePropertiesMember" name="OperatingOfficePropertiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_OperatingPartnershipUnitConversionRateToShares" name="OperatingPartnershipUnitConversionRateToShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OperatingPropertiesMember" name="OperatingPropertiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OtherAdjustmentsAbstract" name="OtherAdjustmentsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OtherFixedRateDebtMember" name="OtherFixedRateDebtMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OtherMarketableSecuritiesMember" name="OtherMarketableSecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_OtherMinorityInterestsIncludingJointVentures" name="OtherMinorityInterestsIncludingJointVentures" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_OtherSegmentReportingMember" name="OtherSegmentReportingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OverAccrualOfIncentiveCompensationCostMember" name="OverAccrualOfIncentiveCompensationCostMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OwnershipInSubsidiaryPercentageLineItems" name="OwnershipInSubsidiaryPercentageLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PartiallyOperationalPropertiesMember" name="PartiallyOperationalPropertiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PartiallyOperationalWholesaleDataCenterMember" name="PartiallyOperationalWholesaleDataCenterMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PaymentsForDerivativeInstrumentOperatingActivities" name="PaymentsForDerivativeInstrumentOperatingActivities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_PaymentsForLeasingCosts" name="PaymentsForLeasingCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_PaymentsOfCapitalDistributionToNoncontrollingInterestInOperatingPartnership" name="PaymentsOfCapitalDistributionToNoncontrollingInterestInOperatingPartnership" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PerformanceShareUnitsMember" name="PerformanceShareUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PrepaidExpensesAndOtherAssetsTextBlock" name="PrepaidExpensesAndOtherAssetsTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember" name="ProjectsInDevelopmentOrHeldForFutureDevelopmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PropertiesInBaltimoreWashingtonCorridorAndGreaterBaltimoreMember" name="PropertiesInBaltimoreWashingtonCorridorAndGreaterBaltimoreMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PropertiesUnderConstructionMember" name="PropertiesUnderConstructionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PropertiesUnderReDevelopmentMember" name="PropertiesUnderReDevelopmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PropertyOperatingExpensesPaid" name="PropertyOperatingExpensesPaid" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_PropertySubjectToEnvironmentalIndemnityLeaseAgreementNumberOfProperties" name="PropertySubjectToEnvironmentalIndemnityLeaseAgreementNumberOfProperties" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_PublicOfferingMember" name="PublicOfferingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_RealEstateAggregateSalesPrice" name="RealEstateAggregateSalesPrice" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstateInvestmentPropertiesNetMember" name="RealEstateInvestmentPropertiesNetMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstateJointVentureLineItems" name="RealEstateJointVentureLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_RealEstateJointVenturesDisclosureTextBlock" name="RealEstateJointVenturesDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstateJointVenturesTable" name="RealEstateJointVenturesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertiesDispositionsTable" name="RealEstatePropertiesDispositionsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertiesStatusAxis" name="RealEstatePropertiesStatusAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertiesStatusDomain" name="RealEstatePropertiesStatusDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertyClassificationAxis" name="RealEstatePropertyClassificationAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertyClassificationDomain" name="RealEstatePropertyClassificationDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertyDisposalAxis" name="RealEstatePropertyDisposalAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertyDisposalDomain" name="RealEstatePropertyDisposalDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertyLocationAxis" name="RealEstatePropertyLocationAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstatePropertyLocationDomain" name="RealEstatePropertyLocationDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedIncomeFromContinuingOperationsTableTextBlock" name="ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedIncomeFromContinuingOperationsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ReconciliationOfPropertyOperatingExpensesFromSegmentsToConsolidatedTextBlock" name="ReconciliationOfPropertyOperatingExpensesFromSegmentsToConsolidatedTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ReconciliationOfSegmentPropertyOperatingExpensesToPropertyOperatingExpensesAbstract" name="ReconciliationOfSegmentPropertyOperatingExpensesToPropertyOperatingExpensesAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_RentalRevenue" name="RentalRevenue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_RestrictedCashAndMarketableSecurities" name="RestrictedCashAndMarketableSecurities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_RestrictedSharesMember" name="RestrictedSharesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_RevenuesFromRealEstateOperationsReceived" name="RevenuesFromRealEstateOperationsReceived" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RutherfordBusinessCenterPortfolioMember" name="RutherfordBusinessCenterPortfolioMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_SalesPriceOfNonOperatingPropertiesSold" name="SalesPriceOfNonOperatingPropertiesSold" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_SalesPriceOfOperatingPropertiesSold" name="SalesPriceOfOperatingPropertiesSold" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SanAntonioMember" name="SanAntonioMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfFairValueOfDebtTableTextBlock" name="ScheduleOfFairValueOfDebtTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ScheduleOfLimitedLiabilityCompanyLlcOrLimitedPartnershipLpManagingMemberOrGeneralPartnerOwnershipInterestTable" name="ScheduleOfLimitedLiabilityCompanyLlcOrLimitedPartnershipLpManagingMemberOrGeneralPartnerOwnershipInterestTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ScheduleOfMortgageAndOtherInvestingReceivablesTable" name="ScheduleOfMortgageAndOtherInvestingReceivablesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfMortgageAndOtherInvestingReceivablesTableTextBlock" name="ScheduleOfMortgageAndOtherInvestingReceivablesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfNetOperatingIncomeFromSegmentsFromServiceOperationsTableTextBlock" name="ScheduleOfNetOperatingIncomeFromSegmentsFromServiceOperationsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfOperatingPartnershipOwnershipTableTextBlock" name="ScheduleOfOperatingPartnershipOwnershipTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfOperatingPropertiesTableTextBlock" name="ScheduleOfOperatingPropertiesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfOperatingPropertyDispositionsTableTextBlock" name="ScheduleOfOperatingPropertyDispositionsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfPrepaidAndOtherAssetsTableTextBlock" name="ScheduleOfPrepaidAndOtherAssetsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfProjectsInDevelopmentOrHeldForFutureDevelopmentTableTextBlock" name="ScheduleOfProjectsInDevelopmentOrHeldForFutureDevelopmentTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ScheduleOfRealEstateTable" name="ScheduleOfRealEstateTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardForDefinedPerformanceTableTextBlock" name="ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardForDefinedPerformanceTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ScheduleOfTradingSecurityLineItems" name="ScheduleOfTradingSecurityLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduledPrincipalAmortizationRepaymentsOfLongTermDebt" name="ScheduledPrincipalAmortizationRepaymentsOfLongTermDebt" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SchillingCircle222And224Member" name="SchillingCircle222And224Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment" name="SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="ofc_SegmentReportingOperatingIncome" name="SegmentReportingOperatingIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedAbstract" name="SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SegmentReportingRevenueReconcilingItemAbstract" name="SegmentReportingRevenueReconcilingItemAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_SegmentReportingTransfersFromNonOperatingProperties" name="SegmentReportingTransfersFromNonOperatingProperties" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SentryGateway1101Member" name="SentryGateway1101Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesGPreferredUnitsMember" name="SeriesGPreferredUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesHPreferredUnitsMember" name="SeriesHPreferredUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesIPreferredUnitsMember" name="SeriesIPreferredUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesJPreferredUnitsMember" name="SeriesJPreferredUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesKPreferredUnitsMember" name="SeriesKPreferredUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesLCumulativePreferredStockMember" name="SeriesLCumulativePreferredStockMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SeriesLPreferredUnitsMember" name="SeriesLPreferredUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEarnedPerformanceShareUnitsPayoutPercentageAbstract" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEarnedPerformanceShareUnitsPayoutPercentageAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodAggeregateFairValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodAggeregateFairValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalIntrinsicValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalIntrinsicValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankEqualsTo25" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankEqualsTo25" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankEqualsTo50" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankEqualsTo50" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankGreaterThanOrEqualsTo75" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankGreaterThanOrEqualsTo75" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankLessThan25" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfEarnedPerformanceShareUnitsPayoutPercentageBasedOnPercentileRankLessThan25" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_ShareBasedCompensationRecognized" name="ShareBasedCompensationRecognized" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceOfExercisedOptions" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceOfExercisedOptions" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SignificantDisposalsLineItems" name="SignificantDisposalsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_SquareFeetOfPropertiesPlacedInService" name="SquareFeetOfPropertiesPlacedInService" nillable="true" substitutionGroup="xbrli:item" type="xbrli:decimalItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_SquareFeetPlacedInServiceOnPropertiesAsOfPriorYearEnd" name="SquareFeetPlacedInServiceOnPropertiesAsOfPriorYearEnd" nillable="true" substitutionGroup="xbrli:item" type="xbrli:decimalItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_StMarysAndKingGeorgeCountiesMember" name="StMarysAndKingGeorgeCountiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_StockIssuedDuringPeriodPerShareValueNewIssues" name="StockIssuedDuringPeriodPerShareValueNewIssues" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_SuburbanMarylandMember" name="SuburbanMarylandMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_TaxIncrementalFinancingBondsAmountIssuedByAnneArundelCountyMaryland" name="TaxIncrementalFinancingBondsAmountIssuedByAnneArundelCountyMaryland" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_TaxIncrementalFinancingObligationAbstract" name="TaxIncrementalFinancingObligationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_TaxableReitSubsidiaryMember" name="TaxableReitSubsidiaryMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_TenantImprovementsOnOperatingProperties" name="TenantImprovementsOnOperatingProperties" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_TenantReimbursementsAndOtherRealEstateOperationsRevenue" name="TenantReimbursementsAndOtherRealEstateOperationsRevenue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_TermLoanFacilityMember" name="TermLoanFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_TowsonPortfolioMember" name="TowsonPortfolioMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_TradingSecurityInvestmentSaleOfShares" name="TradingSecurityInvestmentSaleOfShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="ofc_TradingSecurityOwnershipPercentage" name="TradingSecurityOwnershipPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_UnitsByNameAxis" name="UnitsByNameAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_UnitsClassDomain" name="UnitsClassDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ValuationTechniqueAxis" name="ValuationTechniqueAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ValuationTechniqueDomain" name="ValuationTechniqueDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_VariableRateSecuredDebtMember" name="VariableRateSecuredDebtMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_WarrantsFairValueDisclosure" name="WarrantsFairValueDisclosure" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_WashingtonDcCapitolRiverfrontMember" name="WashingtonDcCapitolRiverfrontMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WeightedAverageConvertiblePreferredStockMember" name="WeightedAverageConvertiblePreferredStockMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WeightedAverageConvertiblePreferredUnitMember" name="WeightedAverageConvertiblePreferredUnitMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WhiteMarshPortfolioMember" name="WhiteMarshPortfolioMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WhiteMarshProfessionalCenterMember" name="WhiteMarshProfessionalCenterMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WholesaleDataCenterMember" name="WholesaleDataCenterMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_YieldAnalysisValuationTechniqueMember" name="YieldAnalysisValuationTechniqueMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
