Abstract: Global warming and the sharp rise in atmospheric CO2 concentration have become an indisputable fact and have a profound impact on forest ecosystem. A comprehensive understanding on the responses of forest ecosystem to global change is essential. The growth response of Schrenk spruce（Picea schrenkiana Fisch. et Mey）,an endemic tree species in the Central Asian arid region,to the climate change and the rising in atmospheric CO2 concentration are lacking. In this study,the Schrenk spruce tree-ring samples from the Ili River Basin were used to establish the tree ring width chronology,stable carbon isotope （δ13 C） series and intrinsic water-use efficiency series（iwue）. The long-term changes of the δ13 C and iWUEand their responses to climate change were analyzed. Meanwhile,the relationship between iWUEand the radial growth of trees was discussed. The results showed that the longterm changes of the iWUEwere affected by atmospheric CO2 concentration（Ca）increase and warming trends,but the main factor that directly affected the inter-annual changes of iWUEwas vapor pressure deficit（VPD）. The increase of the iWUEhad no direct effect on the radial growth of trees. Global warming and Caincrease led to a continuous increase in intrinsic water use efficiency series,but didn’t cause obvious increase on the radial growth of Schrenk spruce.