Abstract: Based on the analysis of the routine monitoring data of Dongfeng Reservoir in Yuxi,Yunnan,combined with the research results,the risk and influencing factors of water environment in the basin were evaluated,and the countermeasures were put forward. The results showed that Dongfeng Reservoir is facing serious water pollution and water ecological damage. The main risks came from the rapid and extensive economic and social development of the basin. The discharge of various pollution sources continues to increase,the water supply of the reservoir is single,the water quality of the reservoir area is difficult to reach the standard steadily,the water quality of the rivers entering the reservoir is poor and the destruction of regional ecology is prominent. The main countermeasures would be taken to strengthen the protection of water resources,enhance the prevention and control of water pollution,implement the ecological restoration of river basins,and improve the capacity building of environmental management.