Abstract: In order to study the landslide mechanisms and responses of a high steep hill with two-side slopes under ground shaking, a high steep hill with two-side slopes near national highway 213 was used as a prototype. A full process from initial deformation to sliding of the slope during ground shaking was simulated by the continuum-medium distinct element method (CDEM). The results show that the stress concentration phenomenon appeared at the top of the sliding mass firstly, and then some tension and shear failure points appeared there, which expanded toward the toe of the sliding mass from the top along the structural plane. At the same time, the number of tension failure points gradually increased. Finally, the toe of the sliding mass broke, and the sliding mass sheared out from the toe, resulting in the landslide. If external conditions such as material parameters were kept the same, the landslide occurrence in the middle of the slope would precede that at the foot, and the starting time of landslide and the arrival time of peak ground acceleration (PGA) were synchronous or the former lagged behind the latter slightly. The PGA of the input seismic wave was amplified with the increase of elevation, regardless of on the steep slope, on the lower slope side, or inside the slope. Generally, the vertical PGA amplification is larger than the horizontal one; the PGA amplification on a steep slope is larger than on a gentle slope, and the PGA amplification on a gentle slope is larger than inside the slope.