Exhibit 1

JOINT FILING STATEMENT

I, the undersigned, hereby express my agreement that the attached Schedule 13D (and any amendments thereto) relating to the ownership by each of the undersigned of ADS of 21Vianet Group, Inc. is filed on behalf of each of the undersigned.

Dated: October 29, 2013

GRANITE GLOBAL VENTURES III L.P.

GGV III ENTREPRENEURS FUND L.P.

BY: GRANITE GLOBAL VENTURES III L.L.C.

ITS: GENERAL PARTNER

By:         /s/ Hany M. Nada

              Hany M. Nada

              Managing Director

GRANITE GLOBAL VENTURES III L.L.C.

By:         /s/ Hany M. Nada

              Hany M. Nada

              Managing Director

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Scott B. Bonham

              /s/ Hany M. Nada

Hany M. Nada

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Thomas K. Ng

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Jixun Foo

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Glenn Solomon

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Jenny Lee

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Fumin Zhuo

              /s/ Hany M. Nada

Hany M. Nada as Attorney-in-fact for Jessie Jin