The paper considers questions connected with Ural - Siberia power link development. Different possible solutions of this problem are represented: three-phase power line on 1150 kV voltage, four-phase power line on 750 /√3 voltage and high voltage direct current power line on ±750 kV voltage. Feasibility studies of these options were performed with paying attention to geographical and climatic conditions of region. Also recommendations of its application are made. Furthermore, on the basis of presented feasibility studies we performed analysis of high and extra high voltage four-phase grid application in existing power system. It is useful for making proper decision in terms of power system development and four-phase grid introduction in united power system of Russia.