Abstract: A medicinal composition comprising a practically water-insoluble anthelmintic compound such as PF1022 substance, which is a cyclic depsipeptide compound, as an active ingredient, and one or more compounds selected from either or both of nonionic surfactants and fats and oils, optionally together with one or more aqueous solvents, wherein the total content of the additives is adjusted to not less than 1 part by weight, preferably from 5 to 50 parts by weight, based on the anthelmintic compound. This composition makes it possible to elevate water-solubility of the anthelmintic comopund and thus enhance its anthelmintic effect.