The paper discusses quantitatively the influence of the Yutian MS7.4 earthquake of March 21,2008 and Wuqia MS6.9 earthquake of October 5,2008 on regional seismicity in Xinjiang,and explains primarily the possible reason of earthquake activity feature in Xinjiang after the Yutian MS7.4 earthquake by analyzing the static Coulomb failure stress change produced by the Yutian MS7.4 earthquake and Wuqia MS6.9 earthquake,and the seismicity feature of MS≥3 earthquakes in the positive Coulomb stress change region of Kashi-Wuqia joint region,the central segment of Tianshan Mountain and Kalpin block.The result shows that the Yutian MS7.4 earthquake of March 21,2008,may encourage the Wuqia MS6.9 earthquake of October 5,2008,and the Yutian MS7.4 earthquake and Wuqia MS6.9 earthquake may change the seismicity state in the central segment of Tianshan Mountain,Kalpin block and Kashi-Wuqia joint region,and encourage the subsequent MS≥3 earthquakes. The paper discusses quantitatively the influence of the Yutian MS7.4 earthquake of March 21,2008 and Wuqia MS6.9 earthquake of October 5,2008 on regional seismicity in Xinjiang, and therefore studied the possible reason of earthquake activity feature in Xinjiang after the Yutian MS7.4 earthquake by analyzing the static Coulomb failure stress change produced by the Yutian MS7.4 earthquake and Wuqia MS6.9 earthquake, and the seismicity feature of MS ≧ 3 earthquakes in the positive Coulomb stress change region of Kashi-Wuqia joint region, the central segment of Tianshan Mountain and Kalpin block. The result shows that the Yutian MS7.4 earthquake of March 21, 2008, may encourage the Wuqia MS6.9 earthquake of October 5, 2008, and the Yutian MS7.4 earthquake and Wuqia MS6 .9 earthquake may change the seismicity state in the central segment of Tianshan Mountain, Kalpin block and Kashi-Wuqia joint region, and encourage the subsequent MS≥3 earthquakes.