The monograph summarizes many years of research by the author and literary data on the biology of the Black Sea amphipods. Their systematic composition (111 species and 5 subspecies) and zoogeographic affiliation are considered. The distribution of amphipods of the Mediterranean complex depending on environmental conditions, the composition of food and food needs of mass and most common species were studied, their number, biomass and total reserves of amphipods of this complex in the Black Sea were determined.