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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 DxO+QWWqDImNZEeOKJsLDQH6zk/d++ph66D6HdnDfpwZFtFuqMQNQHUSC7b/Xj2g
 669fn/77eu3c6zelEjMkzg==

<SEC-DOCUMENT>0000937889-05-000007.txt : 20050611
<SEC-HEADER>0000937889-05-000007.hdr.sgml : 20050611
<ACCEPTANCE-DATETIME>20050609194449
ACCESSION NUMBER:		0000937889-05-000007
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050601
FILED AS OF DATE:		20050609
DATE AS OF CHANGE:		20050609

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			XENOPORT INC
		CENTRAL INDEX KEY:			0001130591
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				943330837
		STATE OF INCORPORATION:			DE

	BUSINESS ADDRESS:	
		STREET 1:		3410 CENTRAL EXPRESSWAY
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95051
		BUSINESS PHONE:		4086167200

	MAIL ADDRESS:	
		STREET 1:		3410 CENTRAL EXPRESSWAY
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95051

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VENROCK ASSOCIATES
		CENTRAL INDEX KEY:			0000937889
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51329
		FILM NUMBER:		05888562

	BUSINESS ADDRESS:	
		STREET 1:		ROOM 5508
		STREET 2:		30 ROCKEFELLER PLAZA
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10112
		BUSINESS PHONE:		2126495600

	MAIL ADDRESS:	
		STREET 1:		ROOM 5508
		STREET 2:		30 ROCKEFELLER PLAZA
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10112
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2005-06-01</periodOfReport>

    <dateOfOriginalSubmission>2005-06-03</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0001130591</issuerCik>
        <issuerName>XENOPORT INC</issuerName>
        <issuerTradingSymbol>XNPT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000937889</rptOwnerCik>
            <rptOwnerName>VENROCK ASSOCIATES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>30 ROCKEFELLER PLAZA, ROOM 5508</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10112</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series D Preferred Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>68333</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>68333</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This amendment is being filed solely to delete disclosure regarding the acquisition of shares of Series D Preferred Stock upon the receipt of a stock dividend paid as an in-kind dividend on the Issuer's outstanding shares of Series D Preferred Stock on June 1, 2005.  This stock dividend was actually paid upon the closing of the Issuer's initial public offering on June 7, 2005 and the receipt of the stock dividend is being reported on a separate Form 4.   No securities were acquired on June 1, 2005.</footnote>
        <footnote id="F2">Each share of Series D Preferred Stock will automatically convert into Common Stock on a 1-for-1 basis concurrently with the closing of the Issuer's initial public offering.</footnote>
        <footnote id="F3">Shares of Preferred Stock are convertible into Common Stock at any time and have no expiration date.  All outstanding shares of Preferred Stock will automatically convert into shares of Common Stock concurrently with the closing of the Issuer's initial public offering.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Bryan E. Roberts, General Partner</signatureName>
        <signatureDate>2005-06-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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