Abstract: The middle region in Gansu Province is arid and most poverty in China.For solution this problem the China government has been dedicated to plan the Taohe River Water Diversion for Irrigation Project since 1950s.The upper reach of Taohe River is the water-taking region of the Project.But analysis on the past 50 years hydrological and meteorological data in Taohe River basin showed a slowly temperature-rising and precipitation-or runoff-decreasing trend.In the past 50 years the precipitation has decreased 43~67 mm and the temperature has increased 0.8℃.Especially,the precipitation has been decreased by 10.2% and the runoff by 35% from 1980s to 1990s.In the past 50 years the multi-annual average total surface and underground water resources quantity was 47.16×10⁸ m³·a^-1 in Taohe River basin.And in 1950s the quantity was 46.25×10⁸ m³·a^-1,but in 1990s the quantity was 33.2×10⁸ m³·a^-1.The decrease of precipitation,runoff and the increase of temperature had resulted in the climate drought and land desertification.Many wetlands or lakes disappeared in Gannan Grassland of Gansu province.All these will influence the Taohe River Water Diversion for Irrigation Project.It has significance to enhance the study on water resources influenced by climate change and present scientific references to this project design and governmental decision-making.

Key words: precipitation, runoff, changing trend, statistical analysis, Taohe River basin