Abstract: The Coastal salt marsh wetland is an important type of coastal blue carbon ecosystems. Fully exploiting the potential carbon sink capacity of salt marsh wetland has essential importance in theoretical studies and practical management to cope with climate change. Based on the distribution of salt marsh vegetation in Yueqing bay, we studied the carbon storage of typical salt marsh vegetation by combining field sampling and laboratory measurements.The results showed that: (1) Spartina alterniflora was the main dominant species in Yueqing bay, and the area of 3352.87 ha. Meanwhile, Suaeda salsa and Phragmites australis were rarely observed in local salt marshes. (2) Spartina alterniflora has a strong carbon storage capacity. The carbon density of Spartina alterniflora was composed of aboveground biomass carbon density, belowground biomass carbon density, and sediment carbon density, with a total of (102.97 ± 9.52) Mg C/ha, of which the sediment carbon density had the maximal contribution, reaching (91.11 ± 9.49) Mg C/ha. (3) The total carbon storage of Yueqing bay was (345244.99 ± 31935.38) Mg C, with an uncertainty level of 12.01 %. Aboveground biomass carbon storage was (16700.11 ± 4814.43) Mg C; belowground biomass carbon storage was (23076.19 ± 10005.75) Mg C; sediment carbon storage was (305468.70 ± 31823.15) Mg C. This study can provide scientific basis for the protection of coastal salt marsh wetland and provide reference for establishing a perfect carbon storage monitoring and evaluation system.