The Ninglang—Yanyuan MS5.7 earthquake that occurred on June 24,2012 caused certain death and property loss.To explore seismogenic tectonic of this earth-quake,we used regional broadband seismic records based on velocity model extracted from Crust Model 2.0 to invert focal mechanism with cut and paste(CAP) method.The strikes,dips,rakes of best focal mechanism solutions are 189°/59°/-40°and 302°/55°/-141°,respectively.It is a Mw 5.4 normal dominant event with strike slip component.The centorid depth provided by CAP method is 4 km.Two other models were employed to better understand errors introduced by velocity model.The mechanisms and magnitudes are similar,while centroid depths range from 4 km to 6 km which are much shallower than results based on traveltime.sPL phase recorded by LGH and pP phases recorded by Australian seismic stations confirmed that the centorid depth is between 4~8 km.North-West distribution of short term aftershocks (two days after mainshock) suggests that this earthquake occurred at Yongning Fault.