Abstract: Coastal wetlands serve as critical ecosystems for blue carbon sequestration. This study employs the InVEST (integrated valuation of environmental services and tradeoffs) model to quantitatively assess changes in carbon storage and its spatial distribution in the coastal wetlands of Hangzhou Bay in 2011−2020. The study also discusses the principal factors influencing carbon sequestration in the wetlands. Findings indicate a reduction in wetland area of 108.46 hectares in these years, yet a marked increase in carbon storage, from 295.05×10⁴ t to 535.59×10⁴ t, with a carbon sequestration of 240.54×10⁴ t. The spatial distribution characteristics reveal that vegetated areas such as Phragmites australis and Spartina alterniflora have significantly higher carbon sequestration per unit area compared to bare tidal flats. By summarizing the spatial and temporal variation patterns of blue carbon in the coastal wetlands of Hangzhou Bay and its influencing factors, this study proposes the following countermeasures in view of blue carbon resource protections i.e., reducing human interference, strengthening ecological restoration and emphasizing monitoring and research in coastal wetland ecosystem.