Recently, several new large ports are developing to handle increasing cargos properly in Korea, i.e., Busan new port, Gwangyang port, Asan port, Pohang new port and so on. Unfortunately, the most of developing new ports are located on soft ground. So a considerable construction cost and period are required for a soft ground improvement.A breakwater should be constructed to maintain proper tranquility in the port even though very soft ground condition. The conventional breakwaters such as a rubble mound breakwater and a caisson breakwater constructed on the soft ground reveal several problems, i.e., an economical low-efficiency, a difficulty in construction, a guarantee of safety, and a seawater pollution due to heavy dredging and pouring materialsIn this study, a new type of breakwater on very soft ground, which can endure the unfavorable conditions of conventional breakwaters, was developed. And its practical use was verified by performing a laboratory model test and a numerical analysis. The consolidation settlements due to self-weight of the breakwater and lateral resistance were examined for various types of breakwater foundation shapes and ground conditions. A construction (installation) sequence of the breakwater was also investigated and the plan for field test was also described briefly.