With Z index according to the Person Ⅲ distribution, REOF and Wavelet analysis methods, the spatial anomaly features and time evolution rule of summer drought and flood in northeast area of China are studied by using the precipitation in June, July and August for the period 1961-2000 from 80 observational stations. The results show that the summer drought and flood in northeast are of China have the obvious characteristics of periodic change, interannual and inter-decade variations. The northeast area of China can be divided into seven dryness/wetness anomaly areas. In each area, the drought and flood coincide relatively.