The wavelet analysis and cumulative anomaly analysis method were used to analyze the changing trends of runoff and precipitation during 1965-2016 in the Fenghe River Basin. Two mutational points in the runoff in the Fenghe River Basin in 1988 and 1997 were revealed. And the slope change ratio of cumulative quantity was adopted to estimate the relative contribution rates of precipitation and human activities on runoff changes in different time periods. Taking 1965-1987 as a reference period, we obtained the contribution rates of precipitation and human activities to the decreased runoff from 1988 to 1996 which were 37.69% and 62.31% respectively, and -11.92% and 111.92% in 1997-2016.