The invention is applied to a radio base station apparatus that allocates a resource to HS-PDSCH and transmits data via the HS-PDSCH to a mobile station. The radio base station apparatus includes: a BLER measurement unit that measures the BLER of a signal received from the mobile station; and a resource allocation unit that, when the measured BLER is equal to or larger than a target value, increases stepwise by a given amount, the amount of data transmit power allocated as the resource to the HS-PDSCH.