A mobile communication system where a mobile station apparatus transmits reception quality information to a base station apparatus, the reception quality information indicating quality of a signal received from the base station apparatus, characterized in that the base station apparatus transmits information for instructing transmission of reception quality information without uplink data included in an uplink data transmission permission signal, and the mobile station apparatus transmits reception quality information without uplink data according to the information for instructing transmission of reception quality information without uplink data. This allows a mobile station apparatus to transmit reception quality information including a large amount of information even if there is no uplink data between the mobile station apparatus and the base station apparatus, and the transmission control flexibly responding to the amount of information and the frequency of transmissions of the reception quality information transmitted from the mobile station apparatus is possible.