To investigate the impingement of fishes on the traveling intake water screens, fishes were collected from the traveling screens at Kori Nuclear Power Plant between April 1987 and March 1989. A total of 102 species was collected during the study period. Gasterosteus aculeatus aculeatus, Engraulis japonicus, Sardinella zunasi, and Trichiurus lepturus were the four most abundant species, and accounted for 97.4% of the total number and 92.2% of the total biomass of fishes collected. Impingement was very high in Febuary and March, but it was low during the rest of the year. There was an inverse relationship between intake water temperature and fish catch.