The present invention relates to a mobile station that controls a transmission rate of user data to be transmitted to a base station. The mobile station according to the present invention includes: a transmission rate control unit configured to decide an instantaneous transmission rate of the user data, based on a parameter notified from a network during establishment of a call, a radio propagation path quality of a radio propagation path between the mobile station and the base station, an average radio propagation path quality of the radio propagation path, and a factor related to a transmission rate, a transmission power or a transmission power ratio notified from the base station.