Members of family Pseudocumidae, order Cumacea are among benthic crustacea that constitute a key part of food chain in the Caspian Sea. Study on identification and distribution of these creatures were conducted under the broad project of "Hydrology and Hydrobiology of the Caspian Sea". During this study which was conducted up to 100m depth (depth of 10, 20, 50 and 100m), 9 species of 4 genera were identified. The four most aboundant species were: Stenocuma diastyloides, Schizorhynchus eudorelloides, Stenocuma gracilloides and Schizorhynchus bilamellatus. Density and number of species sampled from different depths with 4 sampling periods were compared.