Abstract: As an important buffer zone between land and ocean, estuary wetland is a potential sink of microplastics from land and sea. This paper studied the distribution of microplastic pollution in the sediments of the Shuangtai estuary wetland in Liaoning, covering the mariculture area, the tourism area, the reed marsh area and the tidal flat area where Suaeda salsa grows. The result showed that the average abundance of microplastics in the four areas above were (296.89 ± 139.07) items/kg(dw), (171.56 ± 62.82) items/kg(dw), (152.89 ± 21.29) items/kg(dw) and (69.33 ± 6.80) items/kg(dw). The main shapes of microplastics were lamellar, globular, linear and foamy. Microplastics with a particle size of <1 mm accounted for the highest proportion, about 56.3%. The microplastics in the sediment are mainly composed of polystyrene and polyethylene terephthalate, followed by polypropylene, polyethylene and polyvinyl chloride. There were maleic anhydride grafts and chromium and other toxic substances on the surface of some microplastics, which would cause potential ecological risk. The main sources of microplastics in the sediments of Shuangtai estuary wetland may be aquaculture, tourism, petroleum extraction and other activities. In order to explore the distribution characteristics and sources of microplastics in the wetland more comprehensively, it is necessary to increase the layout of sampling points in the wetland and carry out long-term monitoring in the future.