Abstract: A zonal synchronous survey was conducted from January 2021 to December 2022 at Hainan Dongzhaigang Harbor National Nature Reserve, to examine waterbird diversity, seasonal dynamic changes and trend of changes, to provide scientific and technical support for biodiversity conservation and habitat management． A total of 72 species, 13 families, 6 orders of waterbirds were recorded, out of 62703 waterbirds recorded． The seasonal changes of species diversity was winter > autumn > spring > summer． Significant differences were noted in the diversity and seasonal dynamics of waterbird in different habitats; tidal mangroves and breeding ponds were found to be the two most important habitats． Human disturbance and habitat change were important factors affecting the survival of wintering waterbirds． We suggest that conservation measures and ecological restoration strategies be formulated according to the characteristics of bird communities in different habitats, ecological restoration be carried out according to local conditions． Longer term investigations are needed．