A radio power transmission system and a radio power transmission method are provided. The radio power transmission system includes a first radio device and a second radio device including a control signal generator and an antenna. The control signal generator generates a control signal for synchronizing frequencies and phases of power waves, based on signals indicating reception intensities of the power waves in a receiving device receiving the power waves. The antenna transmits the control signal to a plurality of the first radio devices. In the radio power transmission system, the plurality of first radio devices radiate, toward the receiving device, the power waves having the frequencies and phases set to a predetermined value based on the control signal.