Exhibit 4.1

NUMBER

SHARES

SEE REVERSE SIDE FOR CERTAIN DEFINITIONS

CUSIP 31572Q 80 8

FIBROGEN

INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

THIS CERTIFIES THAT

is the owner of

SHARES OF COMMON STOCK

FibroGen, Inc. transferable on the books of the Corporation by the holder hereof in person or by Attorney upon surrender of this certificate properly endorsed. This certificate is not valid until countersigned and registered by the Transfer Agent and Registrar.

IN WITNESS WHEREOF, the said Corporation has caused this certificate to be signed by facsimile signatures of its duly authorized officers.

Dated:

SECRETARY

CHIEF EXECUTIVE OFFICER

COUNTERSIGNED AND REGISTERED:

AMERICAN STOCK TRANSFER & TRUST COMPANY

(New York, New York)

TRANSFER AGENT AND REGISTRAR

BY

AUTHORIZED SIGNATURE

AMERICAN FINANCIAL PRINTING INCORPORATED – MINNEAPOLIS

The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations:

UTMA – Custodian

TEN COM – as tenants in common

(Cust) (Minor)

TEN ENT – as tenants by entireties under Uniform Transfers to Minors

JT TEN – as joint tenants with right of survivorship Act

and not as tenants in common (State)

Additional abbreviations may also be used though not in the above list.

For value received     hereby sell, assign, and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE

(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS INCLUDING POSTAL ZIP CODE OF ASSIGNEE)

Shares of the capital stock represented by the within Certificate, and do hereby irrevocably constitute and appoint Attorney to transfer the said stock on the books of the within-named Corporation with full power of substitution in the premises.

Dated     

NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER.

SIGNATURE GUARANTEED

ALL GUARANTEES MUST BE MADE BY A FINANCIAL INSTITUTION (SUCH AS A BANK OR BROKER) WHICH IS A PARTICIPANT IN THE SECURITIES TRANSFER AGENTS MEDALLION PROGRAM (“STAMP”), THE NEW YORK STOCK EXCHANGE, INC. MEDALLION SIGNATURE PROGRAM (“MSP”), OR THE STOCK EXCHANGES MEDALLION PROGRAM (“SEMP”) AND MUST NOT BE DATED. GUARANTEES BY A NOTARY PUBLIC ARE NOT ACCEPTABLE.