Based on the results of eutrophication surveys of seven reservoirs with different sizes in Maoming in 2019 and 2020,hydrology,nutrients and phytoplankton indexes were selected to evaluate the water quality,eutrophication and phytoplankton of reservoirs in the area.The results showed that the hydrological situation and nutrient environment of each reservoir differed,resulting in different responses in water quality and phytoplankton composition and the variability of phytoplankton community composition in small and medium reservoirs was especially obvious.Therefore,it is necessary to adopt effective methods for eutrophication control according to the local characteristics of each reservoir.