In this paper,we developed 3 tree-ring delta~(13)C chronologies from eastern,central and western on south slope of the Altay Mountains based on standard dendrochronology methods and stable carbon isotope research process.Correlation analysis combined with precipitation data from7 meteorological stations in the Altay Mountains showed that,the tree-ring delta~(13)C series response to summer precipitation on south slope of the Altay Mountains,the highest single correlation index can reach to-0.682 (p<0.0001).The summer precipitation was constructed with regression method.The reconstruction could go back to 1850 and has an adjusted r~2 of 0.453 (1962-2008).The precipitation variability in the past 160 years was analyzed,it shown that the summer precipitation is above normal in the 1850-1871,then the climate have a long dryer period in 1872-1956,and after 1960s until today,it experienced a long wetter period with the climate warming and wetting in Xinjiang.There have a good correlation between summer precipitation and Arctic Oscillation(AO),and Arctic Oscillation may have a greater impact on precipitation variability on south slope of the Altay Mountains.The summer precipitation have the quasi-periodic variations of 11 a (95%),2.7 a (95%),2.4 a(95%),2.1 a(99%)and 2.0 a(99%).