The basic patterns of the deviation distribution of annual precipitation in the Northeast China were defined objectively through the principal component analysis of monthly precipitation from January to December (1961-1978) in 35 meteorological observatories or stations of the Northeast.The eigenvalues and distributive features of precipitation deviation are presented in Table 1 and Fig.1.The first,second and fourth principal components represented wet or dry patterns of the whole area,the pattern of north wet-south dry or north dry -south wet,the pattern of east wet-west dry or east dry-west wet,respectively. The third principal component represented different local precipitation deviation. The author made a dynamic investigation on the formations reasons and processes of dominant patterns of precipitation deviation (Fig.2 and Fig.3) based on the result of principal component anatysis of moathly mean air pressure,and also approached the changing time characteristics of precipitation deviation and reasonally climatic changing differences in the Northeast China (Fig.4 and Fig.5) through the analysis of scoring time-series each month and each year.In order to reveal fully the precipitation differences within the region further,the climatic region-alization of precipitation distributive pattern was carried out with the principal component cluster analysis (Fig.7) and the regional climatic characteristics were clear.Therefore the scientifc basis could be provided for rational arrangement of agriculture,forestry,animal husbandry,production of by-product and fishery.