<SUBMISSION>
<ACCESSION-NUMBER>0001217093-05-000073
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20050630
<FILING-DATE>20050705
<DATE-OF-FILING-DATE-CHANGE>20050705
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>BOSTON PROPERTIES INC
<CIK>0001037540
<ASSIGNED-SIC>6798
<IRS-NUMBER>042473675
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>800 BOYLSTON STREET
<STREET2>SUITE 400
<CITY>BOSTON
<STATE>MA
<ZIP>02199
<PHONE>6172363300
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>800 BOYLSTON STREET
<STREET2>SUITE 400
<CITY>BOSTON
<STATE>MA
<ZIP>02199
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>DALEY WILLIAM M
<CIK>0001183865
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-13087
<FILM-NUMBER>05937266
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>175 EAST HOUSTON STREET
<STREET2>--
<CITY>SAN ANTONIO
<STATE>TX
<ZIP>78205-2233
<PHONE>312-732-4133
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>JP MORGAN CHASE
<STREET2>ONE BANK ONE PLAZA, SUITE 0896
<CITY>CHICAGO
<STATE>IL
<ZIP>60670
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-06-30</periodOfReport>

    <issuer>
        <issuerCik>0001037540</issuerCik>
        <issuerName>BOSTON PROPERTIES INC</issuerName>
        <issuerTradingSymbol>BXP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001183865</rptOwnerCik>
            <rptOwnerName>DALEY WILLIAM M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JPMORGAN CHASE</rptOwnerStreet1>
            <rptOwnerStreet2>ONE BANK ONE PLAZA</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60670</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-06-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>205.14</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>205.14</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2906.18</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Phantom Stock Units convert to Common Stock on a 1-for-1 basis.</footnote>
        <footnote id="F2">The Phantom Stock Units are awarded under the Boston Properties, Inc. 1997 Stock Option and Incentive Plan to non-employee directors who elected to receive Phantom Stock Units in lieu of director compensation fees.  The Phantom Stock Units are to be settled in shares of Common Stock upon the Reporting Person's retirement from the Boston Properties Board of Directors.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Kelli A. DiLuglio, as Attorney-in-Fact</signatureName>
        <signatureDate>2005-07-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
