Abstract：On the basis of a 3D viscoelastic finite element model of lithosphere in North China, we simulated numerically the recent annual changing characteristics of tectonic stress field in the region as follows. 1)The maximum principal extensional stress is 3-9 kPa a\+\{-1\} and its azimuth lie in NNWSSE, the maximum principal compressive stress is about 1-6 kPa
a-1 and its azimuth lie in NEESWW. The whole North China is under the extensional stress field. 2)The maximum principal extensional stress presents high in the west and low in the east,in general,and the stress of whole NE area is high,and the maximum compressive is high in the NE and SN area.This kind of change is benefical for the enhancement of the fault action in Shanxi and Liaoning areas and many speed up the potencial seismogenic process. 3)Annual cumulative rates of coulomb fracture stress in Tanlu fault belt is of a segmentation pattern that the rate of Jiashan-Guangji segment is highest(6 kPa a-1),in AnshanLiaodong Bay segment it is higher(5 kPa a-1) and others are lower (3-4 kPa a-1).
