Based on the broadband waveforms recorded by the Xinjiang and Tibetan Digital Seismic Networks，we inversed the focal mechanism solutions of the main shock，foreshock and MS≥3. 5 aftershocks of the MS7. 3 earthquake，by using the CAP method． The results showed that the focal mechanism of the main shock had Nodal plane I with strike 241° / dip 90° / rake － 22°，and Nodal plane II with strike 331° / dip 68° / rake － 180°，and the focal depth was about 10km． Combined with the active geologic structures of the seismic area，Nodal plane I was identified to be the seismogenic fault plane of the main shock． The direction of P-axis for the main shock was 194°，closed to the NS direction of P-axis of history earthquakes this area． The MS5. 4 foreshock，main shock and 10 aftershocks were strike-slip earthquakes． 6 aftershocks were normal faulting and 2 aftershocks were thrust type earthquakes． 70% of earthquake in the sequence had near NS direction P-axis． The focal depth of this MS7. 3 earthquake sequence distributed 5 ～ 28km，most of the earthquakes occurred within the depth range of 15 ～ 20km，slightly deeper than the focal depth 10km we calculated．