This region is located at 40°—53°30’N and 120°-135°E in the temperate zone.It is one of the main commodity grain bases of China and of areas with aboundant water.The regularity of distribution of runoff is rougthly coincident with that of annual precipitation.Both of them gradually reduce form south-east to north-west.The perennial change values are large,the maximum value of Cv is above 1.0 and the lower value is below 0.3.The annual runoff regularly changes with alternativeplentiful-drought cyclical period and this cyclical period is the longest in China(60—80 years).The analysis of annual runoff in plentiful and drought period can reflect the basic drought and waterlogging situation of this region.The cyclic analysis of annual runoff shows:change of eyclical period at Haerbin Station is different from that at Shuifeng Station(about 52 years for Haerbin Station and about 32 years for Shuifeng Station).This shows there is rather great difference of annual runoff in the northeastern region in geographical distribution.Furthermore,we can prognosticate qualitatively and quantitatively the annual runoff of this region by using the method of mean sliding periodic trend of annual runoff to provide a scientific basis for exploitation and utilization of water resources in a planned way.