Abstract: River as an important pathway for inland microplastics to enter the ocean, their microplastic pollution has received extensive attention. In order to understand the occurrence of microplastics in water of the Hanjiang River (Below the Danjiangkou Dam-Xinglong Section) under the conditions of the first phase of the South-North Water Transfer Project and the operation of the cascade water conservancy projects, the surface water of the Hanjiang River (Below the Danjiangkou Dam-Xinglong Section) and the surface, middle and bottom water of the Wangfuzhou, Cuijiaying and Xinglong Water Conservancy Projects were sampled, and the characteristics of microplastics in water were analyzed. The results showed that the abundance of microplastics in the surface water of the Hanjiang River (Below the Danjiangkou Dam-Xinglong Section) ranged from 4467 n/m³ to 8400 n/m³, with an average of (6260±1431) n/m³. The abundance of microplastics in the intermediate water of Cuijiaying and Xinglong Reservoir was significantly higher than that of surface and bottom water. The particle size of microplastics in surface water of Hanjiang River (Below the Danjiangkou Dam-Xinglong Section) was mainly distributed in 200, 500) μm, with a proportion of 42.5%. With the increase of water depth in the reservoirs, the particle size of microplastics tends to increase, and the particle size of microplastics in the middle and bottom water bodies of the Cuijiaying and Xinglong Water Control Project are mainly 500, 1000) μm.The microplastics in the surface water were mainly fibers, with a proportion of 65.2%, but the shape of the microplastics changed significantly with the water depth of the reservoirs. The proportion of fibers decreased, and the proportion of fragments increased with the water depth. The microplastics in surface water of the Hanjiang River (Below the Danjiangkou Dam-Xinglong Section) were mainly composed of nylon, with a proportion of 65.9%; but the proportion of nylon in the middle and bottom water bodies of the Wangfuzhou, Cuijiaying and Xinglong Water Conservancy Projects decreased, with an average of 57.3% and 43.1%, respectively. The results of this study indicated that microplastics tend to accumulate in the intermediate layer in the reservoir, and the distribution of particle size, shape and material in different water layers are different. Further studies are recommended to investigate the settlement mechanism of microplastics in the reservoir and systematically reveal the environmental behavior and transport pattern of microplastics under the operating conditions of water conservancy projects.