<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="../4_X02.xsl"?><ownershipDocument>    <schemaVersion>X0303</schemaVersion>    <documentType>4</documentType>    <periodOfReport>2010-08-17</periodOfReport>    <notSubjectToSection16>0</notSubjectToSection16>    <issuer>        <issuerCik>0001051470</issuerCik>        <issuerName>CROWN CASTLE INTERNATIONAL CORP</issuerName>        <issuerTradingSymbol>CCI</issuerTradingSymbol>    </issuer>    <reportingOwner>        <reportingOwnerId>            <rptOwnerCik>0001292250</rptOwnerCik>            <rptOwnerName>Abrams David C</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>222 BERKELEY STREET</rptOwnerStreet1>            <rptOwnerStreet2>22ND FLOOR</rptOwnerStreet2>            <rptOwnerCity>BOSTON</rptOwnerCity>            <rptOwnerState>MA</rptOwnerState>            <rptOwnerZipCode>02116</rptOwnerZipCode>            <rptOwnerStateDescription></rptOwnerStateDescription>        </reportingOwnerAddress>        <reportingOwnerRelationship>            <isDirector>1</isDirector>            <isOfficer>0</isOfficer>            <isTenPercentOwner>0</isTenPercentOwner>            <isOther>0</isOther>            <officerTitle></officerTitle>            <otherText></otherText>        </reportingOwnerRelationship>    </reportingOwner>    <nonDerivativeTable>        <nonDerivativeHolding>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>16319</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeHolding>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-08-17</value>            </transactionDate>            <deemedExecutionDate></deemedExecutionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>S</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>1000000</value>                </transactionShares>                <transactionPricePerShare>                    <value>39.91</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>4681532</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>I</value>                </directOrIndirectOwnership>                <natureOfOwnership>                    <value>See Footnote</value>                    <footnoteId id="F1"/>                </natureOfOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-08-18</value>            </transactionDate>            <deemedExecutionDate></deemedExecutionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>S</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>1099748</value>                </transactionShares>                <transactionPricePerShare>                    <value>40.09</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>3581784</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>I</value>                </directOrIndirectOwnership>                <natureOfOwnership>                    <value>See Footnote</value>                    <footnoteId id="F1"/>                </natureOfOwnership>            </ownershipNature>        </nonDerivativeTransaction>    </nonDerivativeTable>    <derivativeTable></derivativeTable>    <footnotes>        <footnote id="F1">The shares represented herein are held by private investment funds of which Mr. Abrams, directly or indirectly, is the managing member of the general partner and/or is the managing member of the investment manager. In such capacities, Mr. Abrams may be deemed to have voting and investment power with respect to all shares being reported herein. Mr. Abrams disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the shares reported herein for purposes of Section 16 or for any other purpose.</footnote>    </footnotes>    <remarks></remarks>    <ownerSignature>        <signatureName>/s/ David C. Abrams</signatureName>        <signatureDate>2010-08-19</signatureDate>    </ownerSignature></ownershipDocument>
