Abstract：The slope failure and landslide hazard will possess the same properties within a range with the same engineering geological conditions. For landslide hazard assessment of a mountainous area，the study of past landslide is very important for evaluating landslide hazard around the past landslide site. Based on the study of mechanism of a past landslide taken place in Kumamoto of Japan，this study firstly proposes the mechanical parameters for landslide hazard evaluating using a 3D slope stability method. For each slope unit in the study area，the critical slip surface，which gives a minimum safety factor of a slope，can be obtained. The affected streams and range of possible landslide masses are analyzed based on the damaged range of the past landslide. Over layered with the layers of infrastructure in geographical information system(GIS)，this hazard map indicates which buildings and road sections are still in the dangerous area.
