Abstract: Xuanmen Bay is a crucial stopover and wintering site for migratory waterbirds along the East Asian-Australasian Flyway (EAAF). Comprising the Xuanmen Bay National Wetland Park and the third phase reclamation area, it provides important habitats for waterbirds. In this study, we analyzed species richness, individual abundance, and the number of threatened species to evaluate the conservation value of this area by using long-term monitoring data of wintering waterbirds in Xuanmen Bay from 2019 to 2024. Additionally, we compared waterbird diversity and community structure between the National Wetland Park and the third phase of the reclamation area to explore the effectiveness of conservation measures within these protected areas. The results indicate that: (1) The number of wintering waterbirds in Xuanmen Bay wetlands continuously increased in recent years, with dabbling birds (primarily Anatidae) as the dominant taxa, supporting five threatened species and five bird species whose population size reaches the Ramsar Convention′s 1% population criteria; (2) The number of dabbling birds in the National Wetland Park was higher than that in the third phase reclamation area (P < 0.01). The number of species and the individual abundance of diving birds were higher than that in the third phase reclamation area (P < 0.05), and diversity indexes (Shannon-Wiener indice and Simpson indice) were significantly higher than that in the third phase reclamation area (P < 0.05). (3) Dabbling birds in two areas were significantly different in the community structure (P < 0.05), and the functional standardization effect values were all less than 0, indicating that dabbling bird communities were functionally clustered, with environmental filtering being the primary driver of community assembly. These results demonstrate the effectiveness of waterbird conservation policies in the National Wetland Park and highlight the need to create heterogeneous habitats to enhance functional diversity. It is recommended that future efforts for conservation of the Xuanmen Bay Nationa Wetland Park be extended to the third phase reclamation area, so as to further improve waterbird diversity.