In this paper,using hydrological data of Gulang River Hydrological Station during 1956-2013in the Caojia Lake Basin,we analyzed the inter-decadal and inter-annual change of runoff depth by linear trends and the 5-year trend of sliding,tested climate mutations on Mann-Kendall method,studied the cycle to climate change in wavelet analysis,the conclusions are following:(1)Spring,summer,autumn and winter runoff depth is abundant in 1960s,but it is relatively lower after 2000,and in these two research period,annual runoff depth is consistent with the change of the seasonal runoff depth;In addition to the winter,other seasons runoff depth are higher than multi-year average in the 1960s;Summer,winter and annual runoff depth are abundant in 1970s and 1990s;(2)variation in spring,summer and autumn runoff depth tended to reduced,but not obvious,which runoff depth in winter displayed an slight increase.Affected by seasonal change,the annual runoff depth also showed a decrease trend;(3)Seasonal runoff depth variation,there were about 4 years,18 years and in addition to the spring,above 28-30 years of cycle during 1956-2013;(4)Mutation reduce of the runoff depth happened in the years of 2008,1961,2007,2007 for spring,autumn,winter and annual,and what 's more,only the summer runoff depth experienced two mutation reduce,respectively,in 1966 and 2007;(5) There was a significant positive correlation between the spring,summer,autumn and annual precipitation and the runoff depth in the study area,and winter precipitation and runoff depth exist no significant negative correlation relationship.