<SUBMISSION>
<ACCESSION-NUMBER>0001217093-05-000081
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20050729
<FILING-DATE>20050802
<DATE-OF-FILING-DATE-CHANGE>20050802
<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>05991826
</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>2005-07-29</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>Dividend Equivalent Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-07-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25.95</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>25.95</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2932.13</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The rights convert to Common Stock on a 1-for-1 basis.</footnote>
        <footnote id="F2">Acquired as quarterly dividends on July 29, 2005. The rights were granted as a component of the Phantom Stock Units that were 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 rights 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>/s/ Kelli A. DiLuglio, as Attorney-in-Fact</signatureName>
        <signatureDate>2005-08-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
