The Jinpingzi Landslide, located in the downstream of the Wudongde Hydro -power Station about 900 m on Jinsha Rive r,was estimated 0.62 billion m3 by using remote sensing technology. The st ability, the movement trend and the possibility of the failure form are the key geological issues tha t have to be solved. On the basis of the geological mapping, drilling and shaft exploring, geophysical exploration and systematic TL dating and rock testing, a thorough investigation on the geological setting and the geological structure o f the landslide mass is represented. And the subzones are plotted out. The mec hanism of the sliding and the evolution of the Jingsha River are analyzed. The c onclusion is that the ancient landslide mass is located in the ancient river ch annel and ancient landslide is stable. This conclusion provides a strong basis t hat the hydro -power station could be constructed in the area and it also play a n important role for study the evolution of the Jinsha River. The achievements a nd the experience can be adopted for the other similar hydro -power projects that will be developed on Jinsha River.