[21Vianet Group, Inc. Announces Changes to the Board of Directors and its Committees BEIJING, China, August 25, 2015 — 21Vianet Group, Inc. (Nasdaq: VNET) (“21Vianet” or the “Company”), a leading carrier-neutral internet data center services provider in China, today announced that its Board of Directors (the “Board”) has appointed Mr. Sean Shao as an independent director, effective on August 24,] [21Vianet Group, Inc. By : Name : Terry Wang Title : Chief Financial Officer 6-K 1 d56481d6k.htm FORM 6-K]

[21Vianet Group, Inc. Reports Second Quarter 2015 Unaudited Financial Results 2Q15 Net Revenues Up 31.7% YOY to RMB866.8 Million 2Q15 Adjusted EBITDA Up 13.2% YOY to RMB149.4 Million Live Conference Call to be Held at 8:00 PM U.S. Eastern Time, August 26, 2015 BEIJING, August 26, 2015 (GLOBE NEWSWIRE) — 21Vianet Group, Inc. (Nasdaq: VNET) (“21Vianet” or the “Company”), a] [FORM 6-K 21Vianet Group, Inc. M5, 1 Jiuxianqiao East Road, Chaoyang District Beijing 100016 The People’s Republic of China (86 10) 8456 2121 x ¨ Form 20-F ¨ ¨ 21Vianet Group, Inc. By : Name : Terry Wang Title : Chief Financial Officer 6-K 1 d67575d6k.htm FORM 6-K]