-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 GzZgW1MCfYrjzHVedbBrFOALprXS7ZUfVhpMgRQaYO6takhIEWYpq/lL8FHcWaX5
 OP44KlQ9AWwtW4DwIYrZAA==

<SEC-DOCUMENT>0001279392-10-000012.txt : 20100331
<SEC-HEADER>0001279392-10-000012.hdr.sgml : 20100331
<ACCEPTANCE-DATETIME>20100331183645
ACCESSION NUMBER:		0001279392-10-000012
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100331
FILED AS OF DATE:		20100331
DATE AS OF CHANGE:		20100331

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PRICE JOHN E
		CENTRAL INDEX KEY:			0001284051

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-21527
		FILM NUMBER:		10721107

	MAIL ADDRESS:	
		STREET 1:		4265 SAN FELIPE
		STREET 2:		8TH FLOOR
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77027

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ENDOWMENT MASTER FUND L P
		CENTRAL INDEX KEY:			0001279392
		IRS NUMBER:				980393260
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4265 SAN FELIPE
		STREET 2:		SUITE 800
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77027
		BUSINESS PHONE:		800-725-9456

	MAIL ADDRESS:	
		STREET 1:		4265 SAN FELIPE
		STREET 2:		SUITE 800
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77027
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001279392</issuerCik>
        <issuerName>ENDOWMENT MASTER FUND L P</issuerName>
        <issuerTradingSymbol>None</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001284051</rptOwnerCik>
            <rptOwnerName>PRICE JOHN E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4265 SAN FELIPE</rptOwnerStreet1>
            <rptOwnerStreet2>8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77027</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Limited Partnership Interests</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>100000</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>0</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The securities are limited partnership interests. Holders are deemed to own a single interest, regardless of the amount of the interest.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>John E.Price</signatureName>
        <signatureDate>2010-03-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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