A radio communication system comprising a wireless terminal and a radio base station, wherein the wireless terminal is configured to switch a beam used for communication with the radio base station among a plurality of beams formed by the radio base station, the wireless terminal comprising an antenna and a power control unit; and the radio base station comprising: an antenna to simultaneously form a plurality of beams; and a power control unit to measure a reception power of each of the beams on the basis of signals received with the beams, the signals being signals for measurement transmitted by the wireless terminal, determine that a beam providing a highest one among the measured reception powers is to be used for communication with the wireless terminal, and, when beam switching is necessary, notify the wireless terminal of a beam switching instruction and a difference in the reception power between a pre-beam-switching beam used before the beam switching and a post-beam-switching beam, the difference in the reception power being determined by the power control unit of the radio base station and being obtained from the reception powers measured for the signals for measurement transmitted by the wireless terminal, the beam switching being performed by the wireless terminal upon reception of the beam switching instruction, wherein when position information on the beam source before the beam switching and position information on the beam source after the beam switching are equal to each other, the power control unit of the radio base station instructs the wireless terminal to determine a transmission power of an uplink signal transmitted from the antenna of the wireless terminal to the radio base station after beam switching, on a basis of: a transmission power of an uplink signal transmitted from the antenna of the wireless terminal to the radio base station before the beam switching; and the notified difference in the reception power. an antenna to simultaneously form a plurality of beams; and a power control unit to measure a reception power of each of the beams on the basis of signals received with the beams, the signals being signals for measurement transmitted by the wireless terminal, determine that a beam providing a highest one among the measured reception powers is to be used for communication with the wireless terminal, and, when beam switching is necessary, notify the wireless terminal of a beam switching instruction and a difference in the reception power between a pre-beam-switching beam used before the beam switching and a post-beam-switching beam, the difference in the reception power being determined by the power control unit of the radio base station and being obtained from the reception powers measured for the signals for measurement transmitted by the wireless terminal, the beam switching being performed by the wireless terminal upon reception of the beam switching instruction, wherein when position information on the beam source before the beam switching and position information on the beam source after the beam switching are equal to each other, the power control unit of the radio base station instructs the wireless terminal to determine a transmission power of an uplink signal transmitted from the antenna of the wireless terminal to the radio base station after beam switching, on a basis of: a transmission power of an uplink signal transmitted from the antenna of the wireless terminal to the radio base station before the beam switching; and the notified difference in the reception power.