Abstract: In order to further explore the occurrence regularity of precipitation and flood disaster, develop and utilize the water resources in Benxi Mountainous area, according to daily precipitation data of Caohekou meteorological station in Benxi from 1953 to 2012, 6 extreme precipitation indexes were analyzed. The results showed that the annual precipitation had significant inter-annual fluctuations, but without significant tendencies, the seasonal precipitation had no obvious change tendency. The annual precipitation days had displayed a decreasing trend since 1974, except the spring precipitation days which had no obvious variation trend, other seasons showed a significant decreasing tendency. The mutation occurred in the summer of 1976 and in the autumn of 1987. Rainfall intensity had no obvious variation trend, the variation of the maximum rainfall of consecutives 5 days was not obvious, but inter-annual difference was significant. The annual extreme precipitation events showed no significant variation trend, periods of more precipitation were 50s, 60s and 80s of the 20^th century.