Abstract: Based on 1965-2012 average daily runoff measured data of control hydrometric station (Xi Kou) in the Tingjiang Basin，and daily precipitation and daily temperature of three meteorological stations in the Tingjiang Basin (Chang Ting, Shang Hang, Yong Ding). Paragraph mean comparison, 5a sliding trend line analysis and cumulative anomaly methods are used to analyze runoff series in recent 50 years. The trend of runoff variation is revealed. The mutation years of runoff variation are identified. The stages of runoff variation are divided. The improved cumulative slope rate comparison method is used to quantitative analysis the contribution rate of the climate change and human activities to runoff variation of Tingjiang in nearly 50 years. The results show that：（1）The runoff shows a down-up- down fluctuation in general, and the mutation year is 1972 and 2001, divided into three stages: the runoff change from 1965 to 1972 (stage A), from 1973 to 2001 (stage B), from 2002 to 2012 (stage C).（2）Comparing with A phase, the contribution rates of climate change to runoff variation in B and C phases are 65.1% and 50.5%, respectively, while the contribution rate of human activities to runoff variation is 34.9% and 49.5%, respectively, visible human activities on the change of runoff with increasingprominent.