This paper sets out to confirm the existence of sea trade routes and cultural links between the Caspian Sea coast and the developed cultures of the Balkan-Danube region during the Eneolithic Period. According to the authors, these communications became possible after the opening of the waterway between the Black and Caspian Seas, which resulted in the formation of the dried-up Kumo-Manych depression. This hypothesis was confirmed by the discovery of similar copper products, anthropomorphic moulding and shell ornaments in various areas of the Balkans, the North-Western Black Sea area and the Caspian Sea coast. In addition, the mutual cultural influence was investigated, which was reflected in megalithic structures, rock carvings, religious cults and funeral rites of the Eneolithic Period cultures. On the basis of the obtained data, the conclusion is made about the existence of active trade and cultural relations between the Varna culture and synchronous cultures of the Northern Black Sea area, Azov and Volga regions, as well as the existence of navigation between the Black and Caspian Seas and developed shipbuilding in the Chalcolithic times.