Abstract:The main characteristics of the general atmospheric circulation in December 2019 are as follows. There were two polar vortex centers in the Northern Hemisphere. The circulation presented a three wave pattern in middle high latitudes. The East Asian trough behaved weakly while the south branch trough was stronger. And the subtropical high was located more westward than that in the same period of normal years. Monthly mean precipitation over China was 11.2 mm, which is 6.7% higher than normal (10.5 mm). Monthly mean temperature over China was －2.7℃, which is 0.5℃ higher than normal (－3.2℃). Three relatively severe rainfall events and three cold air processes with moderate strength occurred in December. In addition, two large scale continuous fog haze weather appeared in the central and eastern part of China during 7-10 and 20-26 December.