The seismic response of landslide is a complicated proposition, and it ' s also the hot spot in recent years, especially after the “ 5.12 ” Earthquake. At present, the dynamic finite element is one of an effective way to solve the dynamic response problem of landslide. In the dynamic finite element, earthquake acceleration is the major factor which reflects the seismic loading, and the impacts of the earthquake on the stress field, displacement field and velocity of the landslide. By using a giant landslide in front of some hydropower dam as an example which was induced by the “ 5.12 ” earthquake, the seismic response analysis of the landslide has been done by a dynamic finite element software, with which the displacement acceleration and the maximum shear stress of the seismic response of the slope have been calculated. Then the status of the reciprocating vibration on the impact of the stability of landslide is illustrated. Finally, the safety factor duration curve of the landslide is got, the calculated results are consistent with the actual displacement of the landslide after the earthquake, it shows that the “ 5.12 ” Earthquake is the direct factor inducing the ancient landslide resurrection.