Based on the observed daily temperature data from 62 stations in North China and NCEP/NCAR reanalysis data from 1961 to 2008,the characteristics of negative accumulated temperature (NAT) change in North China and its circulation background were studied through methods such as EOF,REOF,and wavelet analysis.Results show that:1) the NAT in North China increased consistently,especially in Northern Shanxi Province;2) The NAT in North China can be divided into two subdivisions because the NAT increasing amplitudes were different in east and west.There were both abrupt changes in the west and east of North China,occurring in 1988 and 1986 respectively.A 3-6 years' cycle period was found in the west of North China while it was 2-4 years in the east of North China;3) Changes of Northern Hemisphere winter atmospheric circulation had a close relation with the NAT anomalies in North China.Further composite analysis showed that cold periods were represented by stronger Siberian High,colder winter in North China and larger NAT’s absolute value near the ground while the main influence systems were the East Asian trough and Ural ridge in the middle troposphere.The stronger Ural ridge and the deeper East Asia trough made the cold air activity stronger in North China.In warm periods,it was the opposite situation.