A radio communication system comprising: a radio base station configured to control a mobile station (300A, 300B) by using a transmission power ratio between an uplink physical data channel and an uplink physical control channel; and a radio network controller connected to the radio base station and configured to control the radio base station and the mobile station (300A, 300B), the radio base station including: a storage unit configured to store a table in which a transport format combination indicator of the physical data channel transmitted by the mobile station (300A, 300B) is associated with a transmission power offset that is an offset value of transmission power of the physical data channel to be transmitted by the mobile station (300A, 300B) and is used to determine the transmission power ratio, the table being stored for each E-DCH category of a mobile station; a selector configured to select a transmission power offset associated with the transport format combination indicator from the table corresponding to the E-DCH category of the mobile station; and an informing unit (103, 105) configured to inform the radio network controller of predetermined parameters to be used to determine the transmission power ratio, the predetermined parameters being based on the transmission power offset selected by the selector, and the transport format combination indicator associated with the transmission power offset thus selected, and the radio network controller including: a receiver configured to receive the predetermined parameters informed by the informing unit (103, 105); and a parameter informing unit configured to inform the mobile station (300A, 300B) of parameters that are used to control the transmission power of the mobile station (300A, 300B), and include the predetermined parameters received by the receiver. a radio base station configured to control a mobile station (300A, 300B) by using a transmission power ratio between an uplink physical data channel and an uplink physical control channel; and a radio network controller connected to the radio base station and configured to control the radio base station and the mobile station (300A, 300B), a storage unit configured to store a table in which a transport format combination indicator of the physical data channel transmitted by the mobile station (300A, 300B) is associated with a transmission power offset that is an offset value of transmission power of the physical data channel to be transmitted by the mobile station (300A, 300B) and is used to determine the transmission power ratio, the table being stored for each E-DCH category of a mobile station; a selector configured to select a transmission power offset associated with the transport format combination indicator from the table corresponding to the E-DCH category of the mobile station; and an informing unit (103, 105) configured to inform the radio network controller of predetermined parameters to be used to determine the transmission power ratio, the predetermined parameters being based on the transmission power offset selected by the selector, and the transport format combination indicator associated with the transmission power offset thus selected, and a receiver configured to receive the predetermined parameters informed by the informing unit (103, 105); and a parameter informing unit configured to inform the mobile station (300A, 300B) of parameters that are used to control the transmission power of the mobile station (300A, 300B), and include the predetermined parameters received by the receiver.