<SEC-DOCUMENT>0000899243-22-038230.txt : 20221212
<SEC-HEADER>0000899243-22-038230.hdr.sgml : 20221212
<ACCEPTANCE-DATETIME>20221212160512
ACCESSION NUMBER:		0000899243-22-038230
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211208
FILED AS OF DATE:		20221212
DATE AS OF CHANGE:		20221212

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WIRTH PETER
		CENTRAL INDEX KEY:			0001021041
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38205
		FILM NUMBER:		221457170

	MAIL ADDRESS:	
		STREET 1:		37 HANCOCK STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02114

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Zai Lab Ltd
		CENTRAL INDEX KEY:			0001704292
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			E9
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4560 JINKE ROAD
		STREET 2:		BLDG. 1, 4F, PUDONG
		CITY:			SHANGHAI
		STATE:			F4
		ZIP:			201210
		BUSINESS PHONE:		862161632588

	MAIL ADDRESS:	
		STREET 1:		4560 JINKE ROAD
		STREET 2:		BLDG. 1, 4F, PUDONG
		CITY:			SHANGHAI
		STATE:			F4
		ZIP:			201210
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc4a.xml
<DESCRIPTION>FORM 4/A SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2021-12-08</periodOfReport>

    <dateOfOriginalSubmission>2021-12-08</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001704292</issuerCik>
        <issuerName>Zai Lab Ltd</issuerName>
        <issuerTradingSymbol>ZLAB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001021041</rptOwnerCik>
            <rptOwnerName>WIRTH PETER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ZAI LAB LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>314 MAIN STREET, 4TH FLOOR, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02142</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2021-12-08</value>
                <footnoteId id="F2"/>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>71.36</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Each American Depositary Share (ADS) represents ten Ordinary Shares of the issuer. Our ADSs and Ordinary Shares are fully fungible. For purposes of this Form 4, we are reporting this in terms of ADSs.</footnote>
        <footnote id="F2">On December 8, 2021, the Reporting Person filed a Form 4 that inadvertently reported that the Reporting Person acquired ADSs directly. This amendment reflects the indirect ownership of the acquired ADSs.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Bruce A. Blefeld, Attorney-in-Fact</signatureName>
        <signatureDate>2022-12-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
