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  <xsd:element id="ofc_IncreaseinInvestmentinUnconsolidatedRealEstateJointVentureinConnectionWithPartialSaleofProperties" name="IncreaseinInvestmentinUnconsolidatedRealEstateJointVentureinConnectionWithPartialSaleofProperties" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="ofc_Number901ElkridgeLandingRoadMember" name="Number901ElkridgeLandingRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number911ElkridgeLandingRoadMember" name="Number911ElkridgeLandingRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number938ElkridgeLandingRoadMember" name="Number938ElkridgeLandingRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number939ElkridgeLandingRoadMember" name="Number939ElkridgeLandingRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number940ElkridgeLandingRoadMember" name="Number940ElkridgeLandingRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number9651HornbakerRoadMember" name="Number9651HornbakerRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number9690DeerecoRoadand375WPadoniaRoadMember" name="Number9690DeerecoRoadand375WPadoniaRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_Number990099109920FranklinSquareDriveMember" name="Number990099109920FranklinSquareDriveMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu" name="NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberOfYearsFollowingConstructionCommencementThresholdAchievementBeforePartnersInterestCanBePurchasedAtFairValue" name="NumberOfYearsFollowingConstructionCommencementThresholdAchievementBeforePartnersInterestCanBePurchasedAtFairValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberofDifferentFormsofShareBasedCompensation" name="NumberofDifferentFormsofShareBasedCompensation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberofJointVenturesWithRedeemableNoncontrollingInterests" name="NumberofJointVenturesWithRedeemableNoncontrollingInterests" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberofPropertiesContributed" name="NumberofPropertiesContributed" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="ofc_NumberofPropertiesReclassifiedToHeldForSale" name="NumberofPropertiesReclassifiedToHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_NumberofRealEstatePropertiesAssetsHeldforsale" name="NumberofRealEstatePropertiesAssetsHeldforsale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_OfficePropertiesMember" name="OfficePropertiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OfficePropertiesUnderConstructionRedevelopmentOrContractuallyCommittedForConstructionMember" name="OfficePropertiesUnderConstructionRedevelopmentOrContractuallyCommittedForConstructionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OldAnnapolisRoadMember" name="OldAnnapolisRoadMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <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_OperatingPropertiesNetMember" name="OperatingPropertiesNetMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonDerivativesIneffectivePortionNetofTax" name="OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIonDerivativesIneffectivePortionNetofTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OtherDevelopmentsIncludingIntercompanyEliminationsMember" name="OtherDevelopmentsIncludingIntercompanyEliminationsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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_OtherLandMember" name="OtherLandMember" 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 abstract="true" id="ofc_OtherMember" name="OtherMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_OtherObligationsMember" name="OtherObligationsMember" 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 id="ofc_OwnershipPercentageSold" name="OwnershipPercentageSold" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_ParagonParkDC21Member" name="ParagonParkDC21Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ParagonParkDC22Member" name="ParagonParkDC22Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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 id="ofc_PartnersCapitalAccountUponFormation" name="PartnersCapitalAccountUponFormation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_PatriotPointDC15Member" name="PatriotPointDC15Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PatriotPointDC16Member" name="PatriotPointDC16Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PatriotPointDC17Member" name="PatriotPointDC17Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PatriotRidgeMember" name="PatriotRidgeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PaymentsofDistributionsRedeemableNoncontrollingInterest" name="PaymentsofDistributionsRedeemableNoncontrollingInterest" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_PaymentsofLeaseIncentives" name="PaymentsofLeaseIncentives" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_PercentageOfResidualDistributableCashFlowsEntitledInExcessOfUnpaidCumulativePreferredReturnsAndReturnOfInvestedCapital" name="PercentageOfResidualDistributableCashFlowsEntitledInExcessOfUnpaidCumulativePreferredReturnsAndReturnOfInvestedCapital" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PercentageOfResidualDistributableCashFlowsEntitledInExcessOfUnpaidCumulativePreferredReturnsAndReturnOfInvestedCashRelatedToRealEstatePartner" name="PercentageOfResidualDistributableCashFlowsEntitledInExcessOfUnpaidCumulativePreferredReturnsAndReturnOfInvestedCashRelatedToRealEstatePartner" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PercentageOfResidualNetCashFlowDistributedToEachPartner" name="PercentageOfResidualNetCashFlowDistributedToEachPartner" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PeriodAfterCessationOfMajorConstructionActivitiesForConsideringPropertyToBeOperationalIfLeasesHaveNotCommencedEarlier" name="PeriodAfterCessationOfMajorConstructionActivitiesForConsideringPropertyToBeOperationalIfLeasesHaveNotCommencedEarlier" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PeriodAfterCessationOfMajorConstructionActivitiesForConsideringPropertyToBePartiallyOperationalIfLeasesHaveCommencedEarlier" name="PeriodAfterCessationOfMajorConstructionActivitiesForConsideringPropertyToBePartiallyOperationalIfLeasesHaveCommencedEarlier" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PeriodusedrecoveryanalysisforPotentiallyImpairedLongLivedAssetHeldandUsed" name="PeriodusedrecoveryanalysisforPotentiallyImpairedLongLivedAssetHeldandUsed" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_PrepaidExpensesAndOtherAssetsTextBlock" name="PrepaidExpensesAndOtherAssetsTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ProceedsfromIssuanceofCommonStockNetofIssuanceCosts" name="ProceedsfromIssuanceofCommonStockNetofIssuanceCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" 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_PropertiesCompletedHeldforFutureLeaseMember" name="PropertiesCompletedHeldforFutureLeaseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember" name="PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PropertiesUnderorApprovedforRedevelopmentMember" name="PropertiesUnderorApprovedforRedevelopmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_PropertyOperatingExpensesMember" name="PropertyOperatingExpensesMember" 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_PropertySubjecttoEnvironmentalIndemnityNumberofProperties" name="PropertySubjecttoEnvironmentalIndemnityNumberofProperties" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="ofc_QuarterlyDataLineItems" name="QuarterlyDataLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_QuarterlyDataTable" name="QuarterlyDataTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_RealEstateAccumulatedDepreciationImpairments" name="RealEstateAccumulatedDepreciationImpairments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="ofc_RealEstateAccumulatedDepreciationOtherDispositions" name="RealEstateAccumulatedDepreciationOtherDispositions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RealEstateHeldMember" name="RealEstateHeldMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_RealEstateImpairments" name="RealEstateImpairments" 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 id="ofc_RealEstateOtherDispositions" name="RealEstateOtherDispositions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" 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 id="ofc_ReclassificationofPreferredSharesToBeRedeemedtoLiability" name="ReclassificationofPreferredSharesToBeRedeemedtoLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="ofc_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedIncomeFromContinuingOperationsTableTextBlock" name="ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedIncomeFromContinuingOperationsTableTextBlock" 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 abstract="true" id="ofc_ReconciliationofOperatingIncomefromUnconsolidatedJointVenturestoEquityMethodInvestmentsAbstract" name="ReconciliationofOperatingIncomefromUnconsolidatedJointVenturestoEquityMethodInvestmentsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ReconciliationofPropertyOperatingExpensesfromSegmentstoConsolidatedTableTextBlock" name="ReconciliationofPropertyOperatingExpensesfromSegmentstoConsolidatedTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RedstoneArsenalMember" name="RedstoneArsenalMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RedstoneGatewayMember" name="RedstoneGatewayMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RegionalOfficeMember" name="RegionalOfficeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RegionalOfficeandOtherMember" name="RegionalOfficeandOtherMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_RentalRevenueMember" name="RentalRevenueMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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_RestrictedStockandDeferredSharesMember" name="RestrictedStockandDeferredSharesMember" 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_Route15BiggsFordRoadMember" name="Route15BiggsFordRoadMember" 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 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_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 id="ofc_ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsTableTextBlock" name="ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsTableTextBlock" 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 id="ofc_ScheduleofReconciliationofUnconsolidatedJointVentureNetOperatingIncometoEquityinIncomeofUnconsolidatedEntitiesTableTextBlock" name="ScheduleofReconciliationofUnconsolidatedJointVentureNetOperatingIncometoEquityinIncomeofUnconsolidatedEntitiesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="ofc_ScheduleofShareBasedCompensationbyAwardPerformanceShareUnitsGrantsTableTextBlock" name="ScheduleofShareBasedCompensationbyAwardPerformanceShareUnitsGrantsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
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  <xsd:element id="ofc_SegmentReportingOperatingIncome" name="SegmentReportingOperatingIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="ofc_TwoThousandFifteenPropertyAcquisitionsMember" name="TwoThousandFifteenPropertyAcquisitionsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="ofc_TwoThousandandSeventeenOmnibusEquityandIncentivePlanMember" name="TwoThousandandSeventeenOmnibusEquityandIncentivePlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <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_VariableRateDebtMember" name="VariableRateDebtMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_ViennaVirginiaMember" name="ViennaVirginiaMember" 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_WestfieldsCorporateCenterMember" name="WestfieldsCorporateCenterMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WestfieldsParkCenterMember" name="WestfieldsParkCenterMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="ofc_WhiteMarshMarylandMember" name="WhiteMarshMarylandMember" 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:schema>
