Abstract: Wetland ecosystems are powerful carbon sinks, and it is of great significance to investigate the current status of their carbon pools and carbon sequestration potentials to mitigate global warming. Using the data from the first and second wetland resource surveys in the Yangtze River Delta (YRD), the carbon stock, spatial distribution characteristics of the wetland ecosystems in the YRD and their carbon sink potentials were investigated using the inventory method. The findings revealed that, the organic carbon stock of the YRD wetland ecosystems totaled 487.52 Tg. This pool was predominantly comprised of the soil carbon pool (400.82 Tg) and the vegetation carbon pool (85.48 Tg), with minor contributions from the water body carbon pool (1.22 Tg). The soil and vegetation components accounted for over 99% of the wetland ecosystem's carbon pool. Among different wetland types, marsh wetlands exhibited the highest carbon density (139.54 t/hm²), while coastal wetlands boasted the largest carbon stock (168.02 Tg). Among the three provinces and one city within the YRD region, Jiangsu Province had the largest organic carbon stock in wetlands (249.72 Tg), whereas Shanghai Municipality had the smallest (38.08 Tg). A comparison of the two surveys using consistent methodologies showed that the wetland area in the YRD had increased by 2 257.22 km² over the past decade, with a corresponding increase in wetland carbon stock of 1.39 Tg. Thanks to the implementation of ecological restoration projects, wetlands in the YRD, particularly coastal wetlands, demonstrate significant potential for carbon sequestration. These research findings provide a theoretical foundation for a more accurate assessment of the carbon sequestration potential of wetland ecosystems in the YRD region, thereby supporting carbon neutralization efforts and the ecological restoration of degraded wetlands.‌