Fengshan River is one of the central government controlled rives, that often causes damage during the period of typhoons. In September of 2001, the 2nd River Management Office, Water Resource Agency planned to rebuild about 34,544 meters of dikes, with construction cost about NT$ 824 millions, and they were completed in August of 1992. Although there already existed dykes and bank revetments to protect the lives and properties of the residents along two sides of Fengshan River, some of the dykes and bank revetments were collapsed due to floods in recent years, and should be repaired from time to time. Therefore, this project applies Iowa vane theory apply to Fengshan River (Iowa vane is submerged under design flood condition and also called submerged vane), which was developed by the University of Iowa, USA. The submerged vane system can change the direction of flow at outer bank in river bend and at the toe of the dyke to achieve the protection function. This project also develops the submerged vane model and installation procedures for general practical use.