Abstract: Yili region is located in the western part of Xinjiang (42°12'~44°48'N, 80°10'~85°02'E), its terrain slopes. from east to west and is in a sequence of Kokirqin Mountain (in thenorthern part of the Tianshan Mountains), Yili valley, Wusun Mountain, Zhaosu-TekesBasin, and teh sourthern part of the Tianshan Mountais. It belongs to temperate continental cli-mate in Yili region. Along with global warming, clinate change has been paid a great attentionto. In this paper, the dry-humid climate change in Yili region, Xinjiang since recent 40 years is analyzed by using some mathematical statistical methods. Some conclusions can be obtained: a. The average annual and seasonal precipitaion series in Yili region have good representative, theyhave he different dry-humid stages, change periods, and extremely dry or humid years in the recent 40 years. b. There is a good positive correlation between the precipitation in spring, summer and winter and the annual one in Yili region, and there are the significant negative correlations between precipitation and temperature in summer and between temperature in winterand precipitation in spring. C. A sudden change of precipitation in winter occurred from less to more around 1969 in Yili region. d. There is a synchronous change in annual and seasonal pre-cipitation in Yili region and other areas in north Xinjiang as well as in the southeastern part ofKazakhstan, relatively speaking, there are the best positive correlations of precipitation inspring between Yili region and other areas in north Xinjiang and that in winter between Yili re-gion and the southeastern part of Kazakhstan. e. In Yili region, there are the significant corre-lations of precipitation in spring with the eurasian meridional circulation index from April toMay and latitude of polar vorten in April, and in autumn with the intensity of polar vortex fromJune to Setpember last year and longitude of polar vortex frorm April to May.

Key words: Yili Region, dry-humid climate change, meridional circu, ation index