1.Lernaea cyprinacea Linné is parasitic on the skin of bullfrog tadpoles. It is hitherto not known in our country.The parasitic site is at the boundary between the trunk and the tail,where the body is somewhat depressed.The head of the parasite penetrates deeply into the tissue of the host and causes inflammation around the penetration point.This opens the way for bacteria to attack and kill tadpoles. 2.Lernaea cyprinacea Linné living oh the skin of the bullfrog tadpoles is fundamentally identical with that living on the freshwater fishes,except that the body length is shorter than that of the latter(5.2～9.2 mm vs.6.5～22.5 mm). 3.The usual effective concentration of potassium permanganate and the immersion period used to kill the parasites of fishes are unberable to the tad- poles.Spraying the whole pond with low concentration(4～5 PPM)or dipping in higher concentration(10～20 PPM)for alternate short periods has certain curing effect,but the way to total annihilation remains to be found. In order to prevent the dispersion of the disease,it is important to exter- minate the source of the parasites.Spraying the whole pond with 1～2 PPM bleaching powder and potassium permanganate to kill the eggs and larvae of the parasite,isolating the diseased tadpoles and preventing the introduction of infected river water,pond water or water weeds may serve this purpose.