【Objective】Microplastics (< 5 mm in particle size) in the environment as a new type of pollutant have become a widely concerned issue in recent years. Microplastics may pose certain risks to marine ecosystems because they are very small in particle size, high in abundance, and ubiquitous in distribution and hence readily ingested by marine organisms, such as fish, shellfish, etc. and to wetland ecological environments, too. Recent years have witnessed rapid growth of the number of research reports about microplastics pollution the world over, but just initiation in China. In this study, the Le’an River Section of the Poyang Lake, a tract of wetland, was defined as its research site and samples of sediments were collected from the wetland for analysis of content of microplastics so as to explore distribution and sources of the microplastics in the region, and provide some scientific data for studies of microplastic pollution in inland lake and river wetlands. 【Method】This study combined field surveys and sampling for indoor analysis methods. Samples of sediments were collected from the nine sampling sites distributed in three typical sections of the region, that is,, the upper-stream of the Le’an River, the tributary (the Dawu River) of the Le’an River and the mid- and down-streams of the river, for microscopic, SEM-EDS and FTIR analyses. Abundance, surface morphology, composition and source of the microplastics in the sediments was determined. 【Result】 Results show that the microplastics in the surface sediments of the region were composed mainly of those in the shape of fragment (58.3％), fiber (21.5％), films (13.8％) and foam (6.4％). The average of the 9 sampling sites in abundance of microplastics was 1 800 ind•kg^-1,whih tended to be on the high side as compared with the findings of the researches in other areas. The average of the upstream of the Le'an River, the tributary River (Dawu River) and the downstream of the Le'an River, was 1 121 ind•kg^-1, 2 871 ind•kg^-1 and 1 366 ind•kg^-1, respectively, forming an order of tributary > upper-stream > mid- and lower-streams. Source analysis of the microplastics reveals that industrial pollutants discharged from industries in the neighborhood, and plastic wastes discarded from cities and towns alongside the river and fishery activities were the major sources; SEM-EDS analysis shows that the microplastics were weathered to a varying degree with rough surface and apparent tears; And energy spectrum analysis demonstrates that onto the surface of the microplastics adsorbed were substances and elements, such as Si, Fe, Mg, O, Al, Ca, etc., which aggravated hazardness of the microplastics to the environment and the organisms therein. 【Conclusion】There are 4 kinds of microplastics in the sediments of the Le’an River and the Poyang Lake, in terms of morphology, that is, are fragments, foams, films and fibers. The average abundance of microplastics in the region is 1 800 ind•kg^-1, which is sorted to be moderate tending to be on the high side, compared with that of other regions similar in environment. The microplastics come mainly from nearby industries, residential settlements and fishery activities. The microplastics appear to be weathered to a varying degree with rough surface and obvious tears and gibbosities, which lead to expansion of their specific surface areas, and enhancement of their adsorption capacities for organic pollutants, heavy metal ions and microbes, thus aggravating their hazardness to the environment and organisms therein.