Abstract: Large and medium-sized reservoirs are the key foundation for hydropower generation, and studying their spatial distribution is of great significance to water resource allocation and carbon emission reduction. Based on 4748 large and medium-sized reservoirs in China, spatial analysis methods were used to analyze their spatial pattern characteristics and influencing factors from multiple scales. The results show that: ①China's large and medium-sized reservoirs overall have a spatial distribution structure of "multi-core center and ring distribution"; the global Moran index is 0.155, which has obvious spatial correlation characteristics. ②The three provinces of Hunan, Guangdong and Hubei have the largest number of construction projects, accounting for 24.26% of the country's total; more than 50% are distributed in the third tier and with rainfall above 800mm, and the largest number is distributed in mountainous, hilly landform types and the Yangtze River Basin; Hu Huanyong's population dividing line The southeast side accounts for 80.674%; the three major economic belts have the distribution characteristics of "more in the west and less in the east, gathering in the east and scattered in the west". ③The spatial distribution pattern is mainly affected by the total amount of water resources, relevant laws and regulations, fixed asset investment and other factors.