Based on the winter(DJF) daily surface air temperature data from China National Meteorological Information Center and the NCEP/NCAR global reanalysis data,the non-filtering method is applied to extract the low-frequency signals of 10-30 d from the air temperature and atmospheric circulation.The low-frequency air temperature in China in winter from 1979 to 2011 and associated atmospheric circulation characteristics are analyzed,focusing on the influence of the Ural mountain circulation on the low-frequency surface air temperature in China in winter.Results show that:1)the first mode of surface air temperature in winter demonstrates a consistent cold(warm) pattern over most part of China.The variance of 10-30 d low-frequency surface air temperature accounts for more than 30% of the total in the typical years.2)Circulation anomalies in the North Atlantic to the polar region,Ural Mountain and Lake Baikal are significantly related to winter temperature anomalies in China.When the polar vortex is weaker or the NAO is a positive anomaly,the high pressure ridge in the Ural mountain area is stronger,which is conducive to strengthening of Siberian cold high near Lake Baikal at the surface,so that it is cold in China;and vice versa.3)The low-frequency air temperature in China in winter is closely related to the Ural mountain circulation.When the circulation anomaly over the Ural mountain area leads 15 d earlier than the surface air temperature,their relationship is best.That is,the positive height anomalies over the Ural mountain area is conducive to strengthening of the Ural mountain high ridge and Siberian high,in such a way that East Asian winter monsoon is strengthened,which leads to low temperature in China in winter.