<；P>；PROBLEM TO BE SOLVED: To exterminate the parasite eggs on cultured fishes by a method having a high safety, without any harmful effect to a fish body and the environment. <；P>；SOLUTION: Provided is a method for exterminating the parasite eggs on the cultured fishes, which includes adding hydrogen peroxide so as to give 10 to 600 mg/L hydrogen peroxide concentration in a closed water system of a fish-culturing place and irradiating an ultraviolet light of 240 to 370 nm wave length region for 3 to 40 min with a radiation intensity on the water surface of the closed water system of 2 to 30 mW/cm<；SP>；2<；/SP>；, to exterminate the parasite eggs on the cultured fishes. <；P>；COPYRIGHT: (C)2009,JPO&INPIT
