To investigate the species and infection rate of Tripartiella sp in three species of freshwater fish, carp(Cyprinus carpio), goldfish (Crassius auratus) and Korean catfish(Parasilurus asotus), fish cultured in the fish farms next to Yosu and in the western area of Chunbuk province in Korea was examined from April to June, 1996. The infection rate was evaluated after observing the gill and mucous from 130 fish under the microscope. The species of Tripartiella was identified on the basis of the shape and number of denticle according to methods of Bychowsky(1985) after staining the parasites with 2% methy-ene blue solution. All the detected-parasite was classified as Tripartiella differed from Trichodina reported previously in our country. T carassii, T californica, T rhombi from Goldfish, T rhombi from common carp. T californica from Israeli carp and T bychowsky from Korean catfish were observed. In the fish from the fish farms in the western area of Chunbuk province, the infection rate of Tripartiella sp was ranged from 6.7% to 100%, but in neither carp nor goldfish from the farms next to Yosu the parasite detected.