Transaction in Own Shares

Vianet Group plc

(the "Company")

Transaction in own shares

Vianet Group plc announces that on 2nd October 2012 it purchased 240,000 of its 10p ordinary shares at a price of 100.00 pence per ordinary share. The purchased shares will all be held as treasury shares and it is intended that these shares are used for future satisfaction of granted options that may be exercised.

Following the above purchase, the total number of ordinary shares in issue (excluding shares held in treasury) is 27,792,164. The Company holds 456,000 ordinary shares as Treasury Shares.

Enquiries:

James Dickson, Chief Executive/Mark Foster, Finance Director T: +44 (0)1642 358 800

Stephen Keys/Camilla Hume, Cenkos Securities plc T: +44 (0)20 7397 8900