Abstract：Before and after the Wenchuan \%M\%s8.0 earthquake on 12th May 2008,the coseismic deformation changes greatly, the horizontal deformation at PIXI, MYAN, ZHJI and CHDU GPS stations reached 70 cm,31 cm,23 cm,20 cm respectively. The most deformations are towards northwest 45°, nearly the orthogonal direction of the fault, and the right region,i.e. Chengdu plain of the fault appears downward. The results of kinematic GPS data processing show that the maximum deformation of PIXI reached about 1 m during the earthquake. At last, on the basis of the region time recorded at the stations of the Sichuan GPS network,the average S wave velocities from Wenchuan to all the GPS stations of the network are computed.
