The paper presents the focal mechanism solutions of 74 earthquakes with MS≥4.5 from 2003 to 2008 in Xinjiang and analyzes the regional stress field characteristics reflected by these focal mechanism solutions in Xinjiang in this period. Discussion has been made combining with the seismicity image and regional stress field from 1990 to 2008. The result shows that spatial seismic activity patterns of earthquakes with MS≥5 in Xinjiang are quite different between 1990-2003 and 2004-2008. The azimuth of the principal compression stress P axis of focal mechanism solutions is NNW. The change of elevation angles of the principal compression stress P axis in the focal mechanism solutions of mid-strong earthquakes is obviously related with the strong and weak seismic activities in Xinjiang.