-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 T7a/yJYxsSnroZKuuzy2Oh2cY9cMfNi77cJHuU9vYAChmsWCP/BpDMQV7kC4qG6k
 Aqk8G15cAHnc74KIscR+TA==

<SEC-DOCUMENT>0001311761-10-000018.txt : 20100119
<SEC-HEADER>0001311761-10-000018.hdr.sgml : 20100118
<ACCEPTANCE-DATETIME>20100119125034
ACCESSION NUMBER:		0001311761-10-000018
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100115
FILED AS OF DATE:		20100119
DATE AS OF CHANGE:		20100119

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HAWKEN JEFFREY C
		CENTRAL INDEX KEY:			0001214278

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12675
		FILM NUMBER:		10532619

	MAIL ADDRESS:	
		STREET 1:		12200 W OLYMPIC BLVD
		STREET 2:		SUITE 200
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90064

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KILROY REALTY CORP
		CENTRAL INDEX KEY:			0001025996
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				954598246
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		12200 W. OLYMPIC BLVD., SUITE 200
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90064
		BUSINESS PHONE:		3104818400

	MAIL ADDRESS:	
		STREET 1:		12200 W. OLYMPIC BLVD., SUITE 200
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90064
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-01-15</periodOfReport>

    <issuer>
        <issuerCik>0001025996</issuerCik>
        <issuerName>KILROY REALTY CORP</issuerName>
        <issuerTradingSymbol>NYSE: KRC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001214278</rptOwnerCik>
            <rptOwnerName>HAWKEN JEFFREY C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12200 W. OLYMPIC BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90064</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP and COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, par value $0.01 per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2010-01-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1600.1644</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>309203.6548</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, par value $0.01 per share</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2010-01-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>103</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.76</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>309100.6548</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Grant of restricted stock units in respect of dividend equivalents pursuant to the Kilroy Realty 2006 Incentive Award Plan.</footnote>
        <footnote id="F2">Restricted stock units tendered to pay tax withholding.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jeffrey C. Hawken</signatureName>
        <signatureDate>2010-01-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----