Tengchong County of Yunnan Province is located in the southern region of Hengduan Mountain. From July 17 to 19, 2004, an extraordinary rainstorm struck suddenly over Houqiao, Mingguang, Diantan, Gudong, Jietou, Qushi and Zhonghe villages and towns in the central and northern part of Tengchong County. This event triggered landslide and debris flow disasters over a large area. During the catastrophe, nine local residents were killed or disappeared and nearly 136 million RMB of properties damage occurred. This study shows that the rainstorm, with rainfall of 159.6 mm within 24 hours and reoccurring frequency of 60 years, was the main cause of the disaster. Based on the characteristics of the area, the current situation and the tendency for geological hazards to develop, eleven mitigation measures currently in place or possible in the future are put forward.