Based on hydrological data of the Shimen and Jinshi stations from 1960 to 2007, the changing characteristics and causes of the runoff and sediment discharge in the Lishui River were investigated, using Mann-Kendall trend test ，wavelet analysis and double mass analyses. The results show that the annual runoff changes of Shimen and Jinshi stations from 1960 to 2007 are obvious, but there is a significant wet and dry period alternation cycle in 9 year scale. The monthly runoff increases significantly in January and February with the abrupt point in 1998, while it decreases in April and October with the abrupt point in 2004. The annual sediment discharge has a downward trend and the abrupt point is 1998. The runoff in Lishui River was mainly controlled by the rainfall. However, the allocation of the annual runoff is mainly caused by the human disturbances, especially the construction of large reservoirs. The decrease of sediment discharge is influenced by the complex impacts of runoff, the construction of large reservoirs and soil and water conservation.