Abstract: To further analyze the influence of water and soil resources utilization in Yangtze River estuary and the coastal line development on river bed evolution and hydrodynamics variation, on the basis of the result of two large-scale sampling investigation during the dry season of 2012 and 2013, we analyzed the bed material composition, particle size distribution and characteristics of particle size in flood and dry season respectively at Chengtong reach of Yangtze River estuary. The result indicated that the particle size in the main channel is thicker than that on the shoal and in the branch; the particle size decreases from upstream to the downstream generally. The major types of bed materials in the main channel area are fine sand and silt sand while the bed materials are sand silt and clayey silt on the shoal and in branch channel area; in 2012, the content of sand is the largest at this reach, followed by silt and clay.