The Changes of annual runoff at Beibei,Tingzikou,Wudu and Wusheng hydrological stations inthe Jialing River basin from 1960to 2009are investigated using Mann-Kendall trends test,Mann-Kendallabrupt changing test and cumulative average filter method.Results indicate that runoff at all the stationshave a jumping point in 1991.Double cumulative curve analysis between precipitation and runoff suggeststhat precipitation and human activities exert almost the same influence to the runoff reduction during the1990s,except the Wudu Station where the influence by human activities takes a relative higher proportion.