Objective  The establishment of Ramsar Sites aims to ensure effective global conservation of wetlands critical for waterbird habitats, species diversity and climate regulation. Ramsar Sites play a significant role in global biodiversity conservation. Since joining the Ramsar Convention in 1992, China has designated 82 Ramsar Sites. The aim of this study is to explore the distribution patterns of biodiversity, and quantitatively evaluate the effectiveness of biodiversity conservation in these sites.

Method Here, we focuse on wetland plants and waterbirds, and use quantitative analysis to examine the wetland area distribution, species diversity of plants and waterbirds, and population dynamics of rare and endangered waterbirds from 2014 to 2022 across China’s 82 Ramsar Sites.

Result (1) Although China’s Ramsar Sites cover only 3.76% of China’s total wetland area, it has protected 61.22% of the wetland angiosperms and 82.26% of the waterbirds nationwide. Additionally, these sites safeguard 63.64% of nationally protected wetland angiosperms, 85.44% of nationally protected waterbirds, and 90.91% of waterbirds listed as endangered in the China Biodiversity Red List. (2) 78.4% of the rare and endangered species occurred in multiple Ramsar Sites. (3) All of the occurrence rates of waterbirds in Ramsar Sites, the number of species, the population size of rare and endangered waterbirds showed steady growth from 2014 to 2022.

Conclusion This study provides the first quantitative evidence of significant contribution of China’s Ramsar Sites to global biodiversity conservation. It highlights the progressive enhancement of conservation effectiveness from the perspective of rare and endangered waterbirds, underscoring the vital role of these sites in safeguarding biodiversity. In the future, it is essential to enhance regular monitoring of waterbirds in key wetlands while conducting research on the impacts of climate change, hydrological condition changes in habitats, and habitat fragmentation on species and population distribution of waterbirds.