The principles of identifying the most vulnerable groups and species of invertebrate animals are considered, the characteristics of various species of insects, mollusks, crustaceans and earthworms listed in the Red Book of the USSR, as well as recommendations on protection measures for each of these groups of animals are given. Animal diversity is provided to a large extent by the species diversity of invertebrate animals. The protection of rare animal species is only part of the problem of preserving the gene pool of living organisms of our planet.