Abstract: Coastal blue carbon ecosystems are important natural carbon sinks at the plot scale. In the process of economic development and eco-environmental protection, some coastal wetlands have experienced the transformation of “natural coastal wetlands - aquaculture ponds - returning ponds to wetlands”. The paper introduced the functional importance of coastal wetland ecosystem in carbon sinks and its coastal blue carbon sink capacity. In addition, we sorted out the functional characteristics and the change mechanisms of carbon sinks in natural coastal wetlands, aquaculture ponds and“returning ponds to wetlands”. Based on the current research progress, this paper put forward the research shortcomings and envisaged the emphasis of future study, that is, strengthening the long-term continuity research, multi-site comparison research and multi-interface mechanism research. This paper was expected to provide strategic references for improving the carbon sink capacity of coastal wetlands and evaluating the effect of wetlands restoration.