Abstract: Based on the analysis of the structural features of Taiyuan tilting and joint statistics,and the plate tectonics and continental dynamics theory,the characteristics of the ancient tectonic stress field and its evolutionary process are analyzed.It show that Taiyuan tilting is composed of Dongshan anticline,Xishan syncline and Taiyuan rift.Since the Mesozoic era,the tectonic evolution process can be divided into three stages:the late Mesozoic,Paleogene and the Late Cenozoic.The main structure,including the Dongshan anticline,Xishan syncline and the accompanying north-south fold,was formed under the function of the northeast-southwest dextral couple in the late Mesozoic.The sub-structures of the normal faults and the protot ype,distributed equidistantly in the east of the northeast to westeast in the region,were formed under the function of the nort heast-southwest L-couple in Paleogene.In the Late Cenozoic,as the northwest-southeast tensile stress,tensile and subsidence further formed the current tectonic pattern of Taiyuan rift.The stress field is different from plate tectonic dynamic system in different periods,while they have the characteristics of hereditary,and its formation and evolution process agree with conditional transformation and evolution of regional continental dynamics.