Abstract: The tectonic position of adjacent areas in Zhejiang-Jiangxi-Anhui is located in the northern margin of the eastern section of Jiangnan orogenic belt, which have experienced multi-period tectonic movements, including Caledonian Period, Indochinese Period and Yanshanian Period. Fault belts with various orientation and different geological ages were formed during the tectonic movements, and the tectonic movement during Yanshanian Period is the most active. Based on the ESR dating, Ar-Ar dating and geological field investigation, the authors focus on the tectonic activity characteristics in the Late Yanshania. The Ar-Ar dating in Dongyuan deposit area is (113.5±1.1) Ma, and ESR dating of quartz veins in the fault is distributed between 120 and 100 Ma, approximately (115±5) Ma. The ESR dating of quartz veins in the fault of Tongcun rock mass and surrounding rock of Shichangwu Formation in Late Ordovician is distributed between 120.2 and 100.4 Ma. Therefore, this research shows that a strong tectothermal event occurred in Late Yanshanian Period (120~100 Ma) and a tectonic reversal from extrusion to stretch occurred in late and middle Early Cretaceous.