It is urgent to study catastrophic landslides after the huge damage occurred during Typhoon Morakot in Taiwan. In this study, we could effectively study potential catastrophic landslides by using airborne LiDAR-DEM that were derived after Typhoon Morakot. With more detail surveys, modeling(Particle Flow Code) and surface displacement monitoring in some area with important preservation or village, we could understand about the size, coverage and contributing factors of the landslide disaster. This is a take beginning step for these new forms of slope disaster management.