Abstract: The active tectonic pattern and recent stress state in the seismic region of NW Yunnan province are discussed on the basis of field observation and in-situ stress measurements.Data.show that this region is characterized by pull-apart structures which are formed by the movement of two right-lateral strike-slip faults,the Red River and the Zhongdian fractures,and that the crustal stress state in this region is different from those in the surrounding areas.The earthquake distribution in time and space is controlled by the tectonic pattern and relevant stress states.