Taking the history data of drought and flood disasters as research basis in karst area of southwest China from 1900 to 2012, the paper presented the map of frequency distribution of producing drought and flood disaster in southwest China karst area by frequency and age analysis. Through the summary on characteristics of disasters in southwest China karst area, the conclusion is that the frequency of drought appearance is very high,the flood and water-logging happen every year.At the area of occuring drought and flood disasters,the landform develops better. Apart from the influence of precipitation,the occurance of drought and flood disaster is also affected by other factors.