The prediction of velocity of landslide is a quite complex problem. By using the vertical slice method
the velocity of landslide mass is calculated by the kinematics principle. Then this vertical slice method is applied to a landslide case in Three Gorges Reservoir area. The acceleration and velocity of the landslide mass are analyzed by the vertical slice method. The discontinuous deformation analysis (DDA) is also adopted to simulate the movement process of landslide. The velocities of landslide predicted by the DDA agree well with the ones by the vertical slice method. By using the DDA to simulate the landslide
the initiation of failure and the subsequent kinematics process can be understood clearly.