All research results identify that the mode of the decrease of reservoir level is key mode to control stability of the landslide and must be control mode in harness of the landslide.

In this paper,based on Analysis on mechanism of Dingzhuang industry area Landslides and the author,s practical experiences,the four factors of landslides occurrence are presented,which are intrinsic factor,drop in water level of reservoir,torrential and earthquake.

Discussion on fall of level at the down reach of dams;

Both the sudden drawdown of reservoir water level and rainstorm infiltration become major factors that effect on the stability of landslide.

It is needed to confirm the position of shallow water table in the reservoir banks under combination of rainfall and reservoir fluctuation conditions.