-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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MIC-Info: RSA-MD5,RSA,
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 /O3Q4Q8Rjb6c9zk2GA142g==

<SEC-DOCUMENT>0001393065-10-000004.txt : 20100310
<SEC-HEADER>0001393065-10-000004.hdr.sgml : 20100310
<ACCEPTANCE-DATETIME>20100310140528
ACCESSION NUMBER:		0001393065-10-000004
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
FILED AS OF DATE:		20100310
DATE AS OF CHANGE:		20100310
EFFECTIVENESS DATE:		20100310

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EATON VANCE INSTITUTIONAL SENIOR LOAN FUND
		CENTRAL INDEX KEY:			0001093610
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			E9

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-109600
		FILM NUMBER:		10669953

	BUSINESS ADDRESS:	
		STREET 1:		TWO INTERNATIONAL PLACE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
		BUSINESS PHONE:		617-482-8260

	MAIL ADDRESS:	
		STREET 1:		TWO INTERNATIONAL PLACE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
</SEC-HEADER>
<DOCUMENT>
<TYPE>D/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0603</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001093610</cik>
        <entityName>EATON VANCE INSTITUTIONAL SENIOR LOAN FUND</entityName>
        <issuerAddress>
            <street1>c/o Eaton Vance Management</street1>
            <street2>TWO INTERNATIONAL PLACE</street2>
            <city>BOSTON</city>
            <stateOrCountry>MA</stateOrCountry>
            <zipCode>02110</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>617-482-8260</issuerPhoneNumber>
        <jurisdictionOfInc>CAYMAN ISLANDS</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Other</entityType>
        <entityTypeOtherDesc>Exempt Company under the Companies Law(2001 Revision) of the Cayman Islands</entityTypeOtherDesc>
        <yearOfInc>
            <overFiveYears>true</overFiveYears>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Management</firstName>
                <lastName>Eaton Vance</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Two International Place</street1>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02110</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Robert</firstName>
                <middleName>J.</middleName>
                <lastName>Whelan</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Eaton Vance Management</street1>
                <street2>Two International Place</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02110</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Executive Officer of the Manager</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Thomas</firstName>
                <middleName>E.</middleName>
                <lastName>Faust Jr.</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Eaton Vance Management</street1>
                <street2>Two International Place</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02110</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Executive Officer of the Manager</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Frederick</firstName>
                <middleName>S.</middleName>
                <lastName>Marius</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Eaton Vance Management</street1>
                <street2>Two International Place</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02110</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Executive Officer of the Manager</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>A. John</firstName>
                <lastName>Murphy</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Eaton Vance Management</street1>
                <street2>Two International Place</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02110</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Executive Officer of the Manager</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Duncan</firstName>
                <middleName>W.</middleName>
                <lastName>Richardson</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Eaton Vance Management</street1>
                <street2>Two International Place</street2>
                <city>Boston</city>
                <stateOrCountry>MA</stateOrCountry>
                <zipCode>02110</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Executive Officer of the Manager</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Private Equity Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>9999999997-09-011498</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>1999-03-26</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isEquityType>true</isEquityType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>1000000</minimumInvestmentAccepted>
        <salesCompensationList>
            <recipient>
                <recipientName>Eaton Vance Distributors, Inc.</recipientName>
                <recipientCRDNumber>None</recipientCRDNumber>
                <associatedBDName>None</associatedBDName>
                <associatedBDCRDNumber>None</associatedBDCRDNumber>
                <recipientAddress>
                    <street1>Two International Place</street1>
                    <city>Boston</city>
                    <stateOrCountry>MA</stateOrCountry>
                    <zipCode>02110</zipCode>
                </recipientAddress>
                <statesOfSolicitationList>
                    <value>All States</value>
                </statesOfSolicitationList>
            </recipient>
        </salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>841786027</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>38</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>EATON VANCE INSTITUTIONAL SENIOR LOAN FUND</issuerName>
                <signatureName>A. John Murphy</signatureName>
                <nameOfSigner>A. John Murphy</nameOfSigner>
                <signatureTitle>Vice President of Manager</signatureTitle>
                <signatureDate>2010-03-10</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----