Abstract: The neotectonic activity of a minor fault zone on the Southwest margin of Yangzi platform has been studied based on analysis and comparison of the microstructural features of deformed rocks within and outside the fault zone.According to thermoluminesccne dating it is proposed that after Pleistocene there would be more than one active period of the fault.The strees of the main period was up to 700 bars.The strain and stress of the rocks within the fault during the faulting process were significantly greater than those in the rocks outside the fault.