Abstract: As the most mature, economical and large-scale development potential green flexible regulation power supply of power system, pumped storage power station plays an important role in peak and valley filling, frequency modulation and phase modulation, emergency standby and so on.Based on the site selection planning of small and medium-sized pumped storage power stations in 26 provinces (autonomous regions and municipalities), this paper summarized the development status of small and medium-sized pumped storage power stations, comprehensively analyzed the resource distribution, construction conditions and development economy of small and medium-sized pumped storage power stations, and puts forward the development orientation and main measures.The results showed that a total of 586 small and medium-sized pumped storage census resource sites with a total installed capacity of about 139.5 million kW had been proposed in relevant provinces across the country, and 97 sites with a total installed capacity of 26.32 million kW had been recommended for planning.The site resources showed the characteristics of "multiple points and wide areas", among which the southern region had the most sites, and the northeast region had relatively few sites.Compared with large pumped storage power stations, small and medium-sized pumped storage power stations have the advantages of flexible layout of roots, small footprint, short construction period, basically no relocation of the population, easy to avoid sensitive objects, and convenient access to the system conditions.In terms of the economy of the planning recommended sites, the economy of the southern city was the best, the economy of the Central China city was the second, and the economy of the northwest region was the worst.Based on this, some suggestions were put forward, such as supplementing large-scale pumped storage, which could improve the friendliness of new energy, enhance the terminal support of power grid, strengthen planning guidance, protect site resources, and promot market participation.