Abstract: Caofeidian sea area is the only waterway and harbor basin suitable for building a large-sized berth of 300 000 tons without excavation in Bohai Bay. In Caofeidian harbor area, the stability of the coastal system consisting of shoals and inlets under natural conditions is a key point. The harbor could be developed only if the coastal system is stable. The characteristics of waves, tidal currents, sedimentation and seabed evolution in the Caofeidian near-shore area is briefly described, and the trend of stability of shoals and channels is predicted based on the research on the formation of the coastal system. Engineering effect of some projects is studied such as the dam linking the Caofeidian island and the coastline, the shoal reclamation and the construction of ore terminals. The analysis results show that the deposition and erosion of the sea bed in front of Caofeidian foreland will reach its equilibrium 2-3 years after the construction.