LEGAL OPINION To: Zai Lab Limited 4560 Jinke Road Bldg. 1, 4F, Pudong, Shanghai People's Republic of China

1, 4F, Pudong, Shanghai

terms used herein and not otherwise defined herein shall have the same meanings described in the Registration Statement.

Enforcement of Civil Procedures. We have advised the Company that there is uncertainty

as to whether the courts of the PRC would: (i) recognize or enforce judgments of United States courts obtained against the

Company or directors or officers of the Company predicated upon the civil liability provisions of the securities laws of the United

States or any state in the United States; or (ii) entertain original actions brought in each respective jurisdiction against

the Company or directors or officers of the Company predicated upon the securities laws of the United States or any state in the

have further advised the Company that the recognition and enforcement of foreign judgments are provided for under the PRC Civil

Procedures Law. PRC courts may recognize and enforce foreign judgments in accordance with the requirements of the PRC Civil Procedures

Law based either on treaties between the PRC and the country where the judgment is made or on principles of reciprocity between

jurisdictions. The PRC does not have any treaties or other form of reciprocity with the United States or the Cayman Islands

that provide for the reciprocal recognition and enforcement of foreign judgments. In addition, according to the PRC Civil Procedures

Law, courts in the PRC will not enforce a foreign judgment against the Company or the Company's directors and officers if

that the judgment violates the basic principles of PRC law or national sovereignty, security or public interest. As a result,

it is uncertain whether and on what basis a PRC court would enforce a judgment rendered by a court in the United States or in

the Cayman Islands. Under the PRC Civil Procedures Law, foreign shareholders may originate actions based on PRC law against the

Company in the PRC, if they can establish sufficient nexus to the PRC for a PRC court to have jurisdiction, and meet other procedural

requirements, including, among others, the plaintiff must have a direct interest in the case, and there must be a concrete claim,

a factual basis and a cause for the suit. However, it would be difficult for foreign shareholders to establish sufficient nexus

to the PRC by virtue only of holding the Company's ADSs or ordinary shares.

addition, it will be difficult for U.S. shareholders to originate actions against the Company in the PRC in accordance with the

PRC Laws because the Company is incorporated under the laws of the Cayman Islands and it will be difficult for U.S. shareholders,

by virtue only of holding the Company's ADSs or ordinary shares, to establish a connection to the PRC for a PRC court to

have jurisdiction as required under the PRC Civil Procedures Law.

or fraudulent; (iii) judicial discretion with respect to the availability of injunctive relief, the calculation of damages,

and the entitlement of attorneys' fees and other costs; and (iv) the discretion of any competent PRC legislative, administrative

or judicial bodies in exercising their authority in connection with the interpretation, implementation and application of relevant

is rendered to you for the purpose hereof only, and save as provided herein, this Opinion shall not be quoted nor shall a copy

be given to any person (apart from the addressee) without our express prior written consent except where such disclosure is required

to be made by applicable law or is requested by the SEC or any other regulatory agencies.

consent to the use of this Opinion in, and the filing hereof as an exhibit to, the Registration Statement. In giving such consent,

we do not thereby admit that we fall within the category of the person whose consent is required under Section 7 of the U.S.

Securities Act of 1933, as amended, or the regulations promulgated thereunder.

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