A wireless communication system (100) includes a plurality of mobile stations (30, 40), a macro base station (10), and a femtocell base station (20) that communicatively connects to a registered mobile station. The femtocell base station (20) includes: a handover execution unit (25) that, when a communication quality of a received signal received from one mobile station which is not a registered mobile station satisfies a predetermined condition and a communication connection to another mobile station is made, hands over the communication connection of another mobile station to the macro base station (10); and a transmission power control unit (26) that, when a received signal is received from one mobile station which is not a registered mobile station and the communication connection to another mobile station is not made, suppresses power of a transmission signal transmitted to the mobile station.