For many years, it is one of the confused questions to almost all the researchers that how to consider the effect of the water on the landslide revival. According to statistics, 95% landslide is related to the water's effect, including underground water and surface water. Thus, how does the water work on the slope stability, and how can we identify the water pressure in the landslide? The paper. take Maliuzui, Landslide occurred on August 1998 in Chongqing city of the Changjiang(Yangtze) River as an example. The configuration and structure character of Maliuzui Landslide's and the influencing factors(such as the rainfall process) of the landslide revival and deformation are introduced in the paper. The landslide's genetic mechanism is analyzed, which provides the basis for landslide control project. With the consideration of the effect of groundwater, Maliuzui Landslide genetic mechanism is numerically simulated with the discrete, element method (DEM) in this paper. Study indicated that a vast amount of surface water, also including the rising or descending of the river water level, was forced to infiltrate into the old landslide mass during a heavy rainfall period, causing the groundwater level to several meters higher than that in the low water season, resulting in enormous dynamic pressure and static buoyancy, which are the directly causes to Muliuzui landslide revival.