<SUBMISSION>
<ACCESSION-NUMBER>0001179110-04-000691
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040105
<FILING-DATE>20040107
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>HOLLIDAY MARC
<CIK>0001216194
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-13199
<FILM-NUMBER>04513804
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>C/O SL GREEN REALTY CORP
<STREET2>420 LEXINGTON SUITE 1900
<CITY>NEW YORK
<STATE>NY
<ZIP>10170
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>SL GREEN REALTY CORP
<CIK>0001040971
<ASSIGNED-SIC>6798
<IRS-NUMBER>133956775
<STATE-OF-INCORPORATION>MD
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>420 LEXINGTON AVENUE
<STREET2>ATTN: STEVEN KAHN
<CITY>NEW YORK
<STATE>NY
<ZIP>10170
<PHONE>2125942700
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>420 LEXINGTON AVENUE
<STREET2>ATTN: STEVEN KAHN
<CITY>NEW YORK
<STATE>NY
<ZIP>10170
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2004-01-05</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0001040971</issuerCik>
        <issuerName>SL GREEN REALTY CORP</issuerName>
        <issuerTradingSymbol>SLG</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001216194</rptOwnerCik>
            <rptOwnerName>HOLLIDAY MARC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SL GREEN REALTY CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>420 LEXINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10170</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Chief Executive Officer</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>common stock</value>
</securityTitle>
<transactionDate><value>2004-01-05</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>270000</value>
</transactionShares>
<transactionPricePerShare><footnoteId id="F1"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>475000</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes><footnote id="F1">Not Applicable</footnote>
</footnotes>
<ownerSignature><signatureName>Marc Holliday</signatureName>
<signatureDate>2004-01-07</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
