The western and southern coasts in Korea are recognized as one of the most appropriate places in the world for developing tide and tidal current energy, since they have the geographical features like a Rias coast as well as the strong tides. Tidal power plants(TPP) make use of the rise and fall of sea water level due to tide. A large volume of seawater sluices into a tidal basin so that the water level difference between inside and outside of the basin is utilized to generate electricity. On the other hand, tidal current power plants(TCPP) employ water turbine generators to convert the kinetic energy of strong tidal currents into electricity. The first attempt for constructing TPP is Sihwa TPP. The construction of Sihwa TPP with the installed capacity of 254MW is expected to be completed by 2010. The first target site for developing the tidal current energy is the Uldolmok, where the strongest tidal current in Korea occurs. The construction of pilot TCPP of 1MW was completed in May 2009. The construction works for developing tidal and tidal current energy are planned to be undertaken at several proposed sites.