<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0708</schemaVersion>

    <submissionType>D</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0002116552</cik>
        <entityName>March EXP I LP</entityName>
        <issuerAddress>
            <street1>Walkers Corporate Limited</street1>
            <street2>190 Elgin Avenue</street2>
            <city>George Town, Grand Cayman</city>
            <stateOrCountry>E9</stateOrCountry>
            <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
            <zipCode>KY1-9008</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>345-949-0100</issuerPhoneNumber>
        <jurisdictionOfInc>CAYMAN ISLANDS</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Other</entityType>
        <entityTypeOtherDesc>Cayman Islands Exempted Limited Partnership</entityTypeOtherDesc>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2022</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>n/a</firstName>
                <lastName>March EXP I GP Limited</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Walkers Corporate Limited</street1>
                <street2>190 Elgin Avenue</street2>
                <city>George Town, Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-9008</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Promoter</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>n/a</firstName>
                <lastName>March Fund Management Limited</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Vistra (Cayman) Limited</street1>
                <street2>Hibiscus Way, 802 West Bay Road</street2>
                <city>Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-1205</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Investment Advisor</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>n/a</firstName>
                <lastName>March Capital Limited</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Suite 1611, 16/F, Tower 535</street1>
                <street2>535 Jaffe Road, Causeway Bay</street2>
                <city>Hong Kong</city>
                <stateOrCountry>K3</stateOrCountry>
                <stateOrCountryDescription>HONG KONG</stateOrCountryDescription>
                <zipCode>00000</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Hong Kong Investment Sub-Advisor</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>n/a</firstName>
                <lastName>March Partners LLC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>3500 South DuPont Highway</street1>
                <city>Dover</city>
                <stateOrCountry>DE</stateOrCountry>
                <stateOrCountryDescription>DELAWARE</stateOrCountryDescription>
                <zipCode>19901</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>United States Investment Sub-Advisor</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Zhen Xi Christopher</firstName>
                <lastName>Lai</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Suite 1611, 16/F, Tower 535</street1>
                <street2>535 Jaffe Road, Causeway Bay</street2>
                <city>Hong Kong</city>
                <stateOrCountry>K3</stateOrCountry>
                <stateOrCountryDescription>HONG KONG</stateOrCountryDescription>
                <zipCode>00000</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Director of the General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Harold</firstName>
                <middleName>Herman</middleName>
                <lastName>Schmitz</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Suite F, 221 1st Street</street1>
                <city>Davis</city>
                <stateOrCountry>CA</stateOrCountry>
                <stateOrCountryDescription>CALIFORNIA</stateOrCountryDescription>
                <zipCode>95616</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Director of the General Partner</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Tsz Ho Tony</firstName>
                <lastName>Lau</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Suite 1611, 16/F, Tower 535</street1>
                <street2>535 Jaffe Road, Causeway Bay</street2>
                <city>Hong Kong</city>
                <stateOrCountry>K3</stateOrCountry>
                <stateOrCountryDescription>HONG KONG</stateOrCountryDescription>
                <zipCode>00000</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Director of the General Partner</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Venture Capital Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06b</item>
            <item>3C</item>
            <item>3C.7</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>false</isAmendment>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2025-11-11</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>1500000</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>200000000</totalOfferingAmount>
            <totalAmountSold>5500000</totalAmountSold>
            <totalRemaining>194500000</totalRemaining>
            <clarificationOfResponse>Includes only securities sold to U.S. investors by the Issuer in reliance on Regulation D (e.g., excludes securities sold to non-U.S. investors in reliance on Regulation S).</clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>3</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>March EXP I LP</issuerName>
                <signatureName>Harold Herman Schmitz</signatureName>
                <nameOfSigner>Harold Herman Schmitz</nameOfSigner>
                <signatureTitle>Director of the General Partner</signatureTitle>
                <signatureDate>2026-03-12</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
