The plasma proteins of fresh water fishes have been fractionated by disc electrophoresis in acrylamide gels utilized as an electrophoretic supporting medium. The species of fishes examined in this experiment were Anguilla japonica, Misgurnus mizolepis, Parasilurus asotus, Siniperca scherzeri, Pelteobagrus fulvidra, Carassius carassius, Cyprinus carpio, and Hemibarbus labeo, obtained in the Han River. Disc electrophoresis was performed as described by Ornstein and Davis. Gels and buffer solution were prepared by the method developed by W.J.Kim. The separation gels were 7% acrylamide gel. The fractionation of plasma proteins showed 13 bands in Anguilla japonica, 10 in Misgurnus mizolepis, 15 in Parasilurus asotus, 12 in Siniperca scherzeri, 11 in Pelteobagrus fulvidra, 13 in Carassius carassius, 9 in Cyprinus carpio, and 13 in Hemibarbus labeo. The patterns of plasma protein on the each species of fishes were different in the number of bands, ratio of contents, relative mobilities, and forms of fractionation.