Development of electric power systems in different regions of the world has been analysed, their quantitative estimations are presented. Top-priority tasks on creation of the Unified electric power system of the world, namely formation of such large electric power systems as USSR-East Europe-West Europe, USSR-USA, USSR-China- Japan et al., are formulated. The main characteristics of straits creating obstacles for setting up intercontinental power lines are reviewed, necessary scientific researches relating both to development of power transmission equipment and methods, and to a new stage of electric power system development are pointed out.