Abstract: In order to study the Wenchuan Mw7.9 earthquake rupture characteristic and slip,we model the dense GPS coseismic deformation using simulated annealing algorithm based on uniform elastic half-space model. We find the GPS coseismic deformation can be modeled well using five rupture segments from Yingxiu to Beichuan combined with one rupture segment from Guanxian to Jiangyou, and the result is better than one which is inferred from seismic wave data or InSAR data. The rupture along Yingxiu-Beichuan is 255-294 km length. The south segment can be separated into upper and lower two layers, and is 30 km depth characterized by dip-slip reverse faulting. The mid-segment characterized by right 1ateral oblique faulting and dip-slip reverse faulting, and the north segment characterized by right 1ateral oblique faulting. The shortest earthquake recurrence interval is 3000-year at Yingxiu segment. The rupture depth 14 km of upper layer is probably the locking depth along the Longmenshan fault. The Wenchuan earthquake maybe arised from block relatively moving and extrusion, sliping at depth or locking at shallow,and break out at weakness.