Genetic algorithm-finite element method (GA-FEM) is applied to the study of tectonic stress field of part of East Asia area. From the observed stress distribution, 2-D elastic plane stress inversion is made to deduce the boundary forces and investigate controlling factors. It is suggested that the continent-continent collision is the dominant factor controlling the Chinese tectonic stress field. The ocean-continent convergence along the subduction zone is an important factor. There exists tensile boundary force along tve marginal sea.Key words: genetic algorithm-finite element method (GA-FEM) tectonic stress field dynamic genetic algorithm inversion of finite element method •

By comprehension of earthquake focal mechanism solutions and the data of in-situ stress measurements, the tectonic stress field in Shanxi region has been summarized, which indicate that the stress state in this region is different from that of its eastern surrounding regions. The next, by fitting the measured data, the boundary forces that influenced the distribution of the stress field in this region has been studied using inversion method. The inversion results showed the following messages: the effect of the boundary force between the blocks is the main determinative factor for the recent tectonic stress field in Shanxi and the regional material and its property is a secondary factor; the horizontal main stress of tectonic stress field in Shanxi region is consistent with the stretch of fault basins.Keywords: Shanxi graben system recent tectonic stress field focal mechanism solution in-situ stress measurement genetic algorithm-finite element method inversion•