Abstract: To reveal the fundamental cause of water use conflicts in middle to down stream of Shiyang Rive Basin, the author used data of human activities, runoff and meteorological observation of this area in recent 60 years, to compare internal relationships between agricultural water resources utilization and ecological environment deterioration in the process of oasis advance and climate change. The results showed that: in the Shiyang river basin, eight rivers’ synthesis runoff was on the decline in the past 60 years. The precipitation tendency rate was 5.1 mm per 10 years in the middle stream, which was greater than 2.5 mm per 10 years in the down stream, but the annual evaporation speed was increased at a rate of 11.6 mm per 10 years in the down stream. The temperature had a slowly rising trend (P＜0.001), the temperature were increased by 1.8 and 1.9℃ in middle and down stream of the past 60 years. The available surface water resources for agriculture reduced. The middle stream population rapidly increased by 99500 people per 10 years (P＜0.001), which was 5.5 times of that of the down stream. The decreasing rate of average per capita farmland area reached 0.119 hm² per 10 years (P＜0.001) in the middle stream, greater than 0.036 hm² per 10 years (P＜0.01) in the down stream, but the increasing speed of irrigation area of security was 0.637 hm² per 10 years (P＜0.01) in the down stream, greater than that in the middle stream, which was 0.451 hm² per 10 years (P＜0.01). The well number increasing speed was 1867.6 per 10 years (P＜0.01) in the down stream, more than that in the middle stream, which was 884.3 per 10 years (P＜0.001). Human excessive exploitation of groundwater resources directly affected the ecological carrying capacity and ecological security. As the temperature continued to rise, the evaporation increased, precipitation weakly increased, and river water, the irrigation area of security and the well number increased rapidly, which increased development and utilization of groundwater resources. That led to water conflicts between agriculture and ecology, between the middle stream and the down stream in the researched area, which was the result of human activity and climate change at the same time.