Consisted of the oases,deserts,basins,plains and surrounding mountains,the vast terri-torial system of Xinjiang is an important component in arid areas of Northwest China.Because the geomorphological features having high mountains are in alternation with basins,the unique water cycle systems and the interior drainage basins,big or small,without hydraulic connections are thus formed.In the water circulating process,the mountains,basins,plains,oases and deserts are connected due to the formation and conversion of the water resources through the streams.The streams from the mountains to the deserts,basins and plains are the main sources of the wa -ter resources in Xinjiang because the runoff formation does not occur in the desert,basin and plain systems.Water resources serve not only as the control factors of the ecology and environ-ment,but also as the material base for socio-economic development.Since the late1980s,precip-itation in Xinjiang has increased by20%～30%,stream runoff has universally increased,water level of the lakes has obviously raised,surface area of the lakes has continuously enlarged,and the groundwater level has raised step by step.The synthetic analyses on the main changes of wa -ter resources,slight increase in temperature,obvious increase in precipitation,etc.,show that the regional climate and hydrology are changing towards the favorable aspect to the socio-economic development in Xinjiang in the context of global climate change.It is predicted that this trend will continue untill the first20years of the21st century.