Abstract: Based on the data of runoff from eight stations in Jinsha River,the distribution and annual variation and the tendency,mutation and periodicity of runoff was analyzed by the stochastic hydrology method.The result showed that the Jinsha River had abundant water with distribute unevenly during year,annual variation small and continued high-water season and dry season obviously.Besides,the annual runoff showed an indistinctive increasing trend with the period of 3 to 5 years,9 years,17-year,and the mutations points in 1966 and 1997 in the past 50 years.