A handover control method comprises a step in which a mobile station measures radio qualities in a plurality of different frequency cells at predetermined measurement intervals and a step in which the mobile station, when determining that the radio quality in a specific frequency cell satisfies a report condition, starts up a timer for the specific frequency cell and, when the timer for the specific frequency cell has expired, transmits to a radio base station a measurement report including the radio quality in the specific frequency cell. The mobile station, even when a timer for a second frequency cell has expired, does not transmit to the radio base station a measurement report including the radio quality in the second frequency cell if a timer for a first frequency cell having a higher priority than the second frequency cell is running.