The affecting factors of earthquake induced landslides were discussed in much view of points. For example, Keefer (1984) analyzed 27 landslides then supposed 5 kinds of affecting factors as following: slope angel, height of slope, weathering, soil, and erosion conditions. Li (1986) reviewed earthquake induced landslides in China and proposed 3 factors to judge the slope stability under earthquake as slope angel, rock type, and underground water level. Yoshimatsu (1997) analyzed the correlation among factors and suggested that following factors have good relation with earthquake induced landslide: width of landslide, length of landslide, shape of slope, and height difference. But these papers did not discuss the correlation among factors quantitatively.