Abstract: Through analysis of Silas Mulun River basin climate data from 1995 to 2012, it indicates that the annual average temperature, evaporation, precipitation in the basin is showed a trend of falling volatility and extreme value than the large difference,and between the interannual change is bigger in the basin. Silas Mulun River basin precipitation mainly concentrated in the summer. In April, June, July and August runoff in more than 5×107m3, accounted for 15.3%, 12.4%,25.5%, 12.4%.Starting in September decreased runoff with precipitation, Affected by the differences between different years precipitation, Silas Mulun River basin runoff is relatively strong,Annual runoff showed a trend of fluctuations to reduce in Silas Mulun river basin, the variation tendency rate of average annual runoff is 3.4 ×108 m3/10 a.There is significant positive correlation from Annual runoff changes and climate conditions in Silas Mulun River basin, Annual runoff increased（or lower）with the interannual temperature, evaporation, rainfall and increase（or decrease）.