This paper proposes a square-wave-voltage power distribution system and describes the problems and solutions of the system. The steep transition of the square-wave voltage causes large overshoot voltage at the output terminal of the power line. In order to control the overshoot, a resonant commutated square-wave inverter (RCSI) is developed. An experimental system for the square-wave power distribution system with the RCSI was built and tested. Several test data show the superiority of the system over the conventional sine-wave-voltage power distribution system: the input capacitor of the rectifier in the proposed system can be made 1/20 of that in the conventional system, and the permissive transmission power increases to twice of the conventional system.