Abstract: Based on observed rainfall data of 81 stations in Xinjiang and the NCEP/NCAR reanalysis data during 1961-2015,the concurrent and individual variations of summer rainfall related to thermal circulation difference between southern and northern Xinjiang are analyzed.The results show that when the summer rainfall both over southern Xinjiang and northern Xinjiang is positive,the water vapor is transported from the Arabian Sea by anomalous cyclone over Central Asia,corresponding to the subtropical westerly jet in Western Asia shifting further south.When the summer rainfall in southern Xinjiang is positive and the summer rainfall in northern Xinjiang is negative,the anomalous cyclone in Central Asia moves southward to 40° N,and the water vapor is transported from Arabian Sea and northwest Pacific,corresponding to the subtropical westerly jet over Western Asia shifting further south.When the summer rainfall over northern Xinjiang is positive and the summer rainfall over south Xinjiang is negative,anomalous anticyclone exiting over Central Asia,anomalous cyclone exiting over Xinjiang and the water vapor is transported from northwest Pacific,corresponding to the intensity of subtropical westerly jet over Western Asia strengthened.When the summer rainfall over individual southern（northern）Xinjiang is positive,anomalous cyclone exiting over south（north）Central Asia and north（south）Central Asia,respectively,corresponding to the subtropical westerly jet over Western Asia shifting further south,and the water vapor is transported from Arabian Sea.