All data used are the summer(JJA) temperature of 91 stations in Northeast China from 1955 to 1998.We use the harmonic analysis to separate interannual and interdecadal variations of summer temperature anomaly,further our study on the spatial and temporal characteristics of the two different time scales,and finally apply the REOF method to demarcate the climatic subarea of temperature anomaly,aiming at looking into the abnormal characteristics of different time scales in local regions.The results show that:1)the interdecadal component of variance is obviously larger than the interannual component in the most part of Northeast China;2)the interdecadal variation character of regional temperature anomaly is mainly a linear rising trend,and the large range anomalous high(low)temperature frequently occurs when the interdecadal and interannual anomaly are both positive(negative);3)the temperature anomaly can be divided into four patterns: southern,northern,eastern and western patterns,in which the interdecadal variation of the southern and western patterns is relatively important,while the interannual variation of eastern and northern pattern is relatively important.