Abstract: Climate change and water resources have been drawn wide attention by the government,academic field and the public. Meanwhile,those issues have a significant effect on the rapid development of economy in arid region of northwest China to some degree. The arid region of northwest China is featured by wide area,accounting for about 1/4 of the total area of the country,and plays an vital role in economic development as China[JP10]’[JP]s energy base. However,water resources system is very fragile and the climate change in arid region is sensitive to the global climate. Therefore,it is necessary to enhance the water resources system in arid region of northwest to address climate change and allocate limited water resources rationally. Based on the previous research results,this paper analyzes the influence factors of social and economic development and ecological security and the impacts of climate change on water resources in arid region of northwest. Moreover,the hot and difficult issues of climate change and water resources are explored,including water vapor source and climate changes,the change trends of glacial ablation and glacier water resources,water cycle process and simulation,and the vulnerability of water systems and water safety threshold,water resources allocation of “Water-eco-social economy”. Finally,the author probes into the impacts of the climate change on the formation and transformation of water resources and the future trends and the effects of climate change on water cycle process and water resource security in arid region of northwest.