Flukes of the genus Clonorchis belong to the group of trematodes of the Chinese lake; their life cycle develops in the body of warm-blooded fish and host fish; they are not eaten by humans. They have medical significance for humans; they parasitize in the bile ducts of the liver and pancreas, and less commonly in other organs. They cause opisthorchiasis, a human disease. The most dangerous distribution is recorded in the basins of the Amur and Ussuri rivers, in the Far East (especially in Primorye), in Altai, in Eastern Siberia, as well as in some areas of Ukraine, Belarus, and the Baltic states. Opisthorchiasis and fascioliasis are widespread mainly in