The Ostracods of crustacean exist from the shoreline to a depth of about 2,800 meters. Ostracods are more often found in areas such as lakes, streams, rivers, marshes, lagoons, seas and oceans. Because these organisms are found in all ecosystems, freshwater, brackish and marine, it is natural to find their fossils in all these areas. Ostracodes are very important in Paleoecology, especially in the absence of foraminifera. Though the Caspian Sea is salty and bitter and contains thirteen thousand salt per unit, it is still quite sweeter than ocean water. This area is a suitable environment for ostracode life. These creatures are in both benthic and pelagic form, though the latter is rare. Species such as leptocythere alifani, Stenocypria fischeri, cyprideis sp., cyprideis littoralis, loxocnoncha gibboida, loxocnoncha eichwaldii, loxocnoncha emendates, and caspiolla liventali are the most well-known species in the southeastern part of the Caspian Sea. This study focused on the identification of ostracod species and recognizing environments that best suit the known variesties