In this paper,Wuhua River,the upper stretch of Hanjiang and the first tributary of Meijiang,was selected as the study area. Based on meteorological and hydrological data over the last 30 years,the paper analyzed runoff and sediment's annual variation tendency, abrupt changes and their relationships, using Cumulative filter,Mann-Kendall(M-K),R/S and Double Mass Curve statistics models and methods. On the basis of human activities and climate change,the paper also explored the relationship between runoff and sediment and contribution rate. The results showed that: 1) The runoff amount presented a decline trend of interannual variability,although not obvious; while sediment transport decreased significantly; 2) The annual runoff amount and sediment transport may tend to continuously decline in the future; 3) The mutational site of runoff is between 1981-1985,1997-2001,and 2004-2008; the mutational site of sediment is 1987; 4) The sediment concentration per unit runoff is relatively small,and the river is in the state of erosion; 5) The contribution of precipitation to runoff change is 73%,and the contribution of human activities to runoff change is 27%; the climate change's contribution rate is 21% to the rapid decreasing of sediment discharge while the human activity's contribution rate is 79%. In summary,precipitation is the key factor influencing runoff amount variation,and human activity is key factor influencing sediment discharge.