Coastal vegetated wetlands (coastal blue carbon wetland ecosystem) sequester atmospheric carbon dioxide at higher rates. Coastal blue carbon wetland ecosystems occupy <2% of the marine seascape, however are estimated to contribute around 50% of the ocean's organic carbon storage, largely within an accreting soil-sediment column. It is important to measure carbon sink rates of different coastal blue carbon wetland ecosystems (mangrove, salt marsh, and seagrass) for estimating carbon neutralization capacity at regional scale, new carbon sequestration after ecological restoration, and promoting carbon trade. In this study, we deeply thought the definition of carbon sink rates of coastal blue carbon wetland ecosystem, proposed the definition of broad and narrow coastal blue wetland carbon sink. Two most common methods for measuring carbon sink rates of coastal mangrove, salt marsh and seagrass meadow ecosystem were introduced, which were ecosystem net carbon fluxes method, and sediment organic carbon accumulation+vegetation net primary productivity (NPP) method. Continuous eddy covariance deployments on single atmospheric towers or benthic frames have been well deployed, and at present is a very important method for measuring ecosystem net carbon fluxes. Organic carbon accumulation down through the wetland sediment column is often taken as the measure of coastal wetland carbon sequestration because of its capacity to record long-term variability and trends. We also deeply analyzed the problem and challenges when measuring carbon sink rates for open coastal salt marsh and seagrass meadow ecosystem; and reviewed the results of estimating blue carbon sinks rates and sizes at national scale in China. Finally, we proposed some basic research domains that needed to strengthen in the measurement of blue carbon sink in China. They included (1) to compare two main methods of measuring blue carbon sink rates in the typical coastal wetland plant communities and habits in China, and establish scientific and feasible measurement methods; (2) to build more integrate and typical observation network of surface elevation and eddy covariance flux towers in coastal blue wetlands; (3) to establish allometric equations of different mangrove plant species and coastal salt-marsh plant species; (4) to study roles and contributions of above-ground NPP of salt-marsh and seagrass meadow ecosystem in carbon sink measurement, and to determine how many detritus and litter overflow from salt-marsh and seagrass meadow into sea; (5) to measure contents of recalcitrant carbon (such black carbon) and macroplastic debris carbon in sediment column, and indentify allochthonous and autochthonous carbon sources in coastal blue carbon wetland ecosystem.