Abstract: In this paper, focal mechanism solutions of 4303 earthquakes occurred in and around the mainland of China (15°~55°N, 65°~125°E) from 1976 to 2018 are collected, and the focal mechanism solutions and the spatial distribution characteristics of the P, T axis are analyzed. Using these focal mechanism solutions, we obtained a 2-D tectonic stress field distribution. The results of stress field inversion show that the strike-slip stress is dominant in most of Yunnan, most of the Tibet Plateau and most of North and South China. The strong collision between the Indian plate and the Eurasian plate controls the western part of China. A large number of fault-type earthquakes are concentrated in the Tibet Plateau and the Tianshan area of active block in the western region. There are also normal fault type earthquakes in the Tibet Plateau interior, and the direction of the stress field changes greatly at 26°N. In the Yunnan-Myanmar active block located south of the eastern tectonic line of the Tibet Plateau, the direction of the maximum principal compressive stress changes from the direction of NNE to the direction of NNW. From the northeast block to the North China block and the South China block, the maximum principal compressive stress direction has a rotational tendency from NE to EW and NW.

Key words: Stress field, Focal mechanisms, Mainland China