Abstract: In both side of Daliushu dam site, so much relaxed rock mass can be found. The earthquake intensity is also very high in this area. In this paper, the relaxed rock mass slope stability,under both natural state and seismic state, has been analyzed by using numerical method. The result shows that under natural state, the slope is stable, but plenty of relief relaxed rock mass can be found in the surface of the slope, and stress focus on the fault. Under seismic state, the slope becomes unstable because the soft-hard lithologic group makes rock mass become more relaxed then before.