[21Vianet Issues CEO Letter to Shareholders BEIJING, Sept. 15, 2014 (GLOBE NEWSWIRE) — 21Vianet Group, Inc. (Nasdaq:VNET) (“21Vianet” or the “Company”), the largest carrier-neutral Internet data center services provider in China, today issued the following letter to its shareholders from Mr. Josh Chen, Co-Founder, Chairman of the Board and the Chief Executive Officer of the Company. Dear Shareholders, My name] [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. Shang-Wen Hsiao Chief Financial Officer 6-K 1 d791142d6k.htm FORM 6-K]

[21Vianet Responds to Allegations Made by a Short Seller BEIJING, Sept. 10, 2014 (GLOBE NEWSWIRE)—21Vianet Group, Inc. (Nasdaq:VNET) (“21Vianet” or the “Company”), the largest carrier-neutral Internet data center services provider in China, issued the following statement in response to allegations made by a short seller today: 21Vianet believes that the allegations made contain numerous errors, unsupported speculation and malicious interpretations] [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. Shang-Wen Hsiao Chief Financial Officer 6-K 1 d787882d6k.htm FORM 6-K]

[21Vianet Announces US$100 Million Share Repurchase Program BEIJING, Sept. 4, 2014 (GLOBE NEWSWIRE) — 21Vianet Group, Inc. (Nasdaq:VNET) (“21Vianet” or the “Company”), the largest carrier-neutral Internet data center services provider in China, today announced that its board of directors has authorized a US$100 million share repurchase program. 21Vianet’s board of directors will review the share repurchase program periodically, and may] [21Vianet Group, Inc. By : : Shang-Wen Hsiao : Chief Financial Officer 6-K 1 d785843d6k.htm FORM 6-K]

[21Vianet Announces US$5 Million Share Repurchase Program BEIJING, September 2, 2014 (GLOBE NEWSWIRE) — 21Vianet Group, Inc. (Nasdaq:VNET) (“21Vianet” or the “Company”), the largest carrier-neutral Internet data center services provider in China, today announced that its board of directors has authorized a US$5 million share repurchase program. 21Vianet’s board of directors will review the share repurchase program periodically, and may] [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. Shang-Wen Hsiao Chief Financial Officer 6-K 1 d783302d6k.htm FORM 6-K]