Abstract: Collapsing and sliding responses of Lengjin valley steep bedding rock slope landslide is triggered by"5.12"Wenchuan earthquake,in Chaping town,An xian country.The key controlling factor of collapsing and sliding of the slope is long duration of strong earthquake force.It had special destruction features in its dynamic processes,the failure mechanism is mainly contained collapsing and sliding.This text use two-dimensional discrete element numerical simulation and analyse the acceleration response rules by the slope internal monitoring data,some conclusions are obtained as following:as the elevation increases,the dynamic response acceleration shows increasing in the trend of nonlinear; as the distance from slope surface decreasing,the dynamic response acceleration increased and the peak acceleration of slope surface was significantly increased; the peak effect of dynamic response acceleration occurred around the crest of the slope.Based on the acceleration dynamic response analysis,the slope collapsing and sliding failure mechanism is analysed.The result show that: first,the slope shattering-cracking and relaxed induced by strong earthquake,joint fissures opened and run through; with the shock effect of the seismic forces periodically,the rock-mass fragmentated and disintegrated in the lower part; the high mass has lost support,and the slope overall shattering-slided by the bedding plane eventually.