Abstract: The Dongying Harbor is a silty coast. The movement of sediments is rather active and the change in deposition and erosion obvious there. Recent coastal engineering construction has made outstanding effects on the dynamic environment. According to the measured bathymetric data in 2007 and 2015, with the methods of depth profiles comparison, numerical simulation and moving velocity comparison, the characteristics and influence factors of erosion and deposition in the Dongying Harbor area are researched in this paper. Results show that the study area is characterized by erosion near coast and deposition offshore. From the Feiyan Shoal to the Dongying Harbor, the balance depth of erosion and deposition change from 9m to 6m. Sediment is easy to move at the Feiyan Shoal southeastwards by the coastal current. As the result, there is stronger erosion of seabed on the Feiyan Shoal. The maximum depth of wave break is about 6m, the balance depth of erosion and deposition near the Dongying Harbor is corresponding to it. Coastal engineering construction has changed the tendency of erosion and deposition in some parts of the research area. The head of breakwaters in the Dongying Harbor is under intense erosion. And deposition appears at the both sides of the breakwaters.