During the autumn of 2013, the surface air temperature was higher than normal and the precipitation amount was above normal in most part of the Northeast China, especially from October to November. The diagnosing results show that the external forcing of higher sea surface temperature in Northwest Pacific Ocean and atmospheric circulation features, may lead to the climatic anomaly in Northeast China. The abnormal circulation pattern with obviously positive phase of Arctic Oscillation, and positive anomaly of geopotential height over Northeast China is unfavorable for cold air to move southward causing higher air temperature in Northeast China for the season. Meanwhile, in mid late Autumn, precipitation anomaly in the Northeast China is mainly influenced by the stronger southeasterly moisture transport from the western North Pacific Ocean.