Abstract:We relocated 7172 earthquakes occurring in the Yunnan area from May,2010 to July,2011 by jointly using the permanent and temporary station records data. Considering the impact of velocity model,we first obtained a 1-D mininum P velocity model with the VELEST method. And then we got 5836 epicenter results by applying the double-difference method,and the resluts show that the seismogenic layer is basically located in the upper and middle crust,and the focal depth is more deeper in western Yunnan. We caculate the b-value of the Yunnan area using the relocated earthquake catalogs,and some new recognitions were achieved:the b-value was gradually reduced with depth,particularly at the depth of 9~10km;and the b-value 3-D distribution of the Yingjiang MS5.8 earthquake sequences showed that the main shock was in the transition zone with high and low b-value.