The tidal pilot plant is being built in the Uldolmok waterway using its strong tidal current with maximum current of about 12 knots, which is revealed from the first direct observation using ADCP, on February, 2002. A series of field observations, along with numerical modeling, have been carried out over the last several years, in order to understand the tidal dynamics and to examine the related variables according to the tidal current power plant (TCPP) operation.