Applying remote sensing and GIS technique this paper attempts to analyze the landslide hazard after two typhoon events. First of all, by comparing the landside data from SWCB and satellite images from FORMOSAT (processed by supervised classification and NDVI index), the landslides of Midulle Typhoon increased 100% for number and 60% for area than that of Toraji Typhoon. The new born landslides located in the valley slope of main course and tributaries in upper stream. Another, over 87% of landslide reacted in Mindulle Typhoon when the precipitation from 300-350mm (Toraji Typhoon) up to 750-1000mm. Secondly, based on GIS database and statistic processing, it shows that the concentration in space may resulted from not only the intensity of precipitation also the geomorphic (steepness of slope) and geological factors (resistance of rock and weakness of structural line). Finally, the vulnerability of landslide hazard in Tachia basin could be shown by the index of unstable formulated by weighting of environmental parameters.