The Chinese seismological station net determined that an MS6.6 earthquake occurred on July 22,2013,at 7:45CST at the border of Minxian and Zhangxian counties in Gansu Province. By the end of August 26,1300aftershocks had occurred in the seismic region of the main earthquake,including one of 5.0~5.9level,one of 4.0~4.9level,and nine of 3.0~3.9level.The largest,with magnitude of 5.6,occurred at 9:12on July 22.This earthquake caused heavy casualties and economic losses. In this study,the cut-and-paste(CAP) method was used to determine that the earthquake was thrust and strike-slip,MWwas 6.1,and the focal depth was 7km.The nodal plane II parameters of the best double-couple are strike 304°,dip 64°,and rake 44°.The strike of the nodal plane had the same trend as that of the Lintan-Tanchang fault,and the characteristic of dip and slip represent left lateral slip,which also corresponds to the Lintan-Tanchang fault.The nodal plane is representative of the seismogenic fault plane.Therefore,the Minxian-Zhangxian Ms6.6earthquake is in osculating correlation with activity of the Lintan-Tanchang fault.