Abstract:The straight reach of the Yangtze estuary is the only way to extend the 12.5 m deepwater channel downstream Nanjing reach of the Yangtze River.The implementation of the Luocheng shoal defending project will lay the foundation for the overall governance programs.On the basis of comprehensive analysis of riverbed evolution characteristics and program effectiveness,we optimize the project layout using the physical model,the mathematical model,as well as the local generalized three-dimensional physical model test and work out the optimized recommendation.The research shows that the implementation of the optimized scheme will be beneficial to maintain the good beach groove pattern on the upper channel of the straight reach of the Yangtze estuary,and control the adverse trends of Luocheng shoal head and the right branch development.The project can achieve the goal of the defending project.The local scour of the project is small,the project is easy to connect with the later scheme,and the 12.5 m deepwater channel’s overall project management improves the channel condition of the straight reach of the Yangtze estuary considerably.The optimized plane scheme of the project is reasonable,which can provide a reference for the engineering design of Luocheng shoal defending project.The effect after implementation of the project shows that this project is good to protect the head of Luocheng shoal,and has curbed the negative trend of erosion.