Abstract: Based on air temperature, precipitation and runoff from 1961 to 2005 in the right bank of the Nenjiang River Basin, the climate change and its influence to water resources were analyzed by cumulative departure method and climate tendency rate. The results indicate that air temperature in the right bank of the Nenjiang River Basin increases obviously in recent 45 years with 0.52 ℃/10 a. The air temperature changes take on the increasing tendency, and the increment is the highest in winter, followed in spring, autumn and summer. Air temperature increases obviously since 1986. On the other hand, precipitation can divide into three periods, i.e. decreasing period from 1961 to 1982, increasing period from 1982 to 1998 and decreasing period from 1998 to now. The change tendency of summer precipitation is similar to that of annual precipitation, and they takes on the weak rising trend with the fluctuation. The annual changes of runoff and precipitation in the main controlling stations in the right bank of the Nenjiang River Basin are synchronous.