Abstract: There is a bank slope of non-matrix structure at some planning Hydroelectric Power Station on the middle of the Jinsha River. The spread of the bank slope is extraordinary thick, which mainly composed with dolomatic brecciated accumulation body. The slope induced a massive block event in the middle of Jin-sha river. Based on the analysis of sample,it happened 19,000 years ago. The landslide investigation has shown that the ancient accumulation body slope is stable. There is no deformation indication and condition of destabilization of the whole slope.