A radio communication system 1 according to an embodiment comprises: a pico cell base station PeNB provided in a communication area of a macro cell base station MeNB and having transmission power lower than transmission power of the macro cell base station MeNB. A resource division ratio is determined with respect to radio resources to be usable as a PDSCH, indicating a ratio of macro cell unusable PDSCH resources and macro cell usable PDSCH resources. The radio resources are assigned to a radio terminal connected to the macro cell base station MeNB, out of the macro cell usable PDSCH resources determined according to the determined resource division ratio. The resource division ratio is determined according to expected throughputs of each of cell edge terminals of the macro cell base station MeNB and the pico cell base station PeNB.