Abstract:The mean variance of daily air temperature over China in winter was used as the index of intra-seasonal variation of air temperature. Its characteristics was analyzed and its circulation background induced by intra seasoual variability of winter temperature in China was explored. The results show that the internal variability of winter temperature in China is generally weakening, and it has obvious response characteristics to the trend of climate warming. The interdecadal change coincides with the interdecadal transition time of the East Asian winter monsoon. When the temperature seasonal variability is abnormally strong, the average circulation field in winter shows a quasi-positive pressure structure, the polar vortex in the stratosphere is weak, the high latitudes in the troposphere distribute similarly to Scandinavian teleconnection type, the middle and low latitudes have a large area of negative anomaly, the near strata of Siberia is strong, and North Atlemtic Oscillation (NAO) is a negative phase. Further analysis shows that NAO can affect the intraseasonal variation of temperature by affecting the high frequency variation of Siberian high pressure. In the end, through extracting the internal variability of atmospheric circulation on four time scales of weather season, the seasonal variability of air temperature is regulated by Siberian high and East Asian cold vortex. In addition, on the synoptic scale, frequent fluctuations of the Aleutian low and stable deactivation of the upper European ridge are closely related to the temperature variability, and the seasonal scales, including Eurasian blocking high and Okhosk Sea blocking high anomalies, have significant effects on the temperature variability.