Abstract:Based on the data obtained since 1951 and the crustal vertical deformation rate calculated from the GPS data obtained from 1999 to 2007, the vertical deformation characteristics in QinghaiTibet block and southern China block, and the relationship between the vertical deformation and both of the occurrence and the development of Wenchuan Ms8.0 earthquake was studied. The results show that Wenchuan Ms8.0 earthquake happened in the vertical deformation rate gradient zone that was the dramatic rising area.The accumulation of deformation strain energy was related with collisions of the IndianEurasian plates, and the vertical uplift of the QinghaiTibet block by strong squeeze in NorthSouth direction at the front edge of the collision of the two plates with the substance movement to the East and SouthEast.