Abstract: The current study explored the distribution of aquatic vegetation, species diversity, community characteristics and succession features of Caohai wetland based on previous results and recently obtained data, and analyzed the primary driving factors of community succession. Results showed that there were 67 species of aquatic plants, which belong to 40 genera and 28 families, and 22 dominant plant association in Caohai wetland in 2016. Compared with results of 1983, both dominant species and preponderant associations changed dramatically. The dominant aquatic plant associations have gradually changed from sedge family to grass family. The alien species Alternanthera philoxeroides in the Caohai wetland has formed an invasion trend in the water fluctuation belt, waterway and wharf, and its population density can reach 70 plants/m² in some regions. The total biomass of aquatic plants of each life in Caohai wetland has increased in the past 30 years, and in 2016 it was 4.1 times that of 1983. Relevant data indicate that human activity, bird migration, water and soil loss, eutrophication, and alien species invasion have influenced the biodiversity and community succession of Caohai wetland.