In winter 2016/2017 (December 2016 to February 2017), East Asian winter monsoon was much weaker than normal, and the Siberian high was weaker, too. Arctic Oscillation (AO) was primarily in a positive phase. For geopotential height anomalies at 500 hPa in Northern Hemisphere, zonal circulation was mainly observed in the midhigh latitudes in Asia, and China was dominated by positive height anomaly. In association with the anomalous circulation, the temperature over China was higher than normal. The average temperature in the winter was -1.5℃, which is 1.9℃ higher than the climate mean (-3.4℃). The winter 2016/2017 was the warmest since 1961. The East Asian winter monsoon and Siberian high in each month of the winter were weaker, and the average temperature in the corresponding month was higher. Actually, the abnormal weaker winter monsoon is correlated with the atmospheric circulation anomaly in the Arctic in summer. The thermal and dynamic conditions of Arctic atmospheric circulation in summer 2016 modulate the effect of autumn Arctic sea ice loss on winter atmospheric variability, and this is unfavorable for the strengthen of the winter monsoon.