Abstract: Taking advantage of the Southwest Region(Sichuan,Yunnan,Guizhou,Chongqing) major geological disaster information and national major geological disasters Yearbook data,statistic 1961-2010 years' different geological hazards(landslides,debris flow),record the time and place of occurrence happened,determine the area of influence. Using 77 observation stations' daily precipitation data,according to the definition of Precipitation Concentration Threshold,and using linear regression method to research the Precipitation Concentration Threshold at the different geological disaster affected zone in the southwest of China. The research shows that :The southwest of China has high Incidence of geological disaster. 1961-2010 years the major time of geological disasters occurred is consistent with precipitation time,Mainly in the June-September,most of which occurred in July. Precipitation is the major factor of geological disasters. The Threshold of landslide,debris flow hazards caused by precipitation has differences at different place in southwest of China,The Threshold of Sichuan Basin region is Maximum,the Yunnan-Guizhou Plateau is followed,Qinghai-Tibet Plateau is minimum. what's more,those hazards are mainly caused by continuous heavy rain.