Introduction and Course of the Investigation.- Geography, Politics and Economy in the Caspian Region.- Legal History and the Present State of Use of the Caspian Resources.- Cooperation Levels in Caspian States Practice in the 1990s Until 2018.- Interrelations Between Territorial Delimitation and the Regime of the Use of the Caspian Sea.- The Regime for the Use of Nonliving Resources in the Caspian Sea.- The Legal Regime of the Living Resources of the Caspian Sea.- The Legal Regime of the Pipelines in the Caspian Sea.- The Legal Regime of Maritime Navigation on the Caspian Sea.- Protection of the Marine Environment of the Caspian Sea.- Concluding Remarks.