The paper draws the topographic characteristics of the landslide induced by Chi-Chi Earthquake and Typhoon Morakot in Ai-Liao catchment, in slate stratum. The result from topographic analysis on the DEM shows 90% landslides induced by earthquake are small than 10 ha, the average slope is 30-50o, and 75% of landslide locates at the ridge or the mountainside of the slope. Oppositely, the 52% landslides induced by typhoon are large than 10 ha, the average slope of landslide is gentle to the one of earthquake landslides and 81% of landslides locates at the mountainside or the toe of slope. The analysis result also demonstrated that a certain degree of deflection usually occurs before a sliding initiation that suggests the deformation (and the subsequent damage) of the massive landslide is progressive. Moreover, the profile curvatures of landslide cases are close to the curvature 1×10-4 (1/m), the landslide possibility rises up at where curvature beyond the value.