It is an objective of the present invention to suppress an influence on a downlink and to appropriately control a transmission rate of uplink user data. A mobile communication system according to the present invention includes: a transmission section for transmitting to a mobile station an exclusive channel for notifying a mobile station of transmission rate information regarding a transmission rate of user data of an uplink channel; and a transmission rate control section for determining transmission rate information to be used by the mobile station and to instruct the mobile station to receive the exclusive channel for notifying the determined transmission rate information. The transmission section transmits, to the mobile station, the exclusive channel for notifying the determined transmission rate information.