In a mobile communication system including SRNC and DRNC for controlling a plurality of base station, and mobile stations, a method for controlling power of TFCI field for DSCH if DSCH-associated DCH exists in a soft handover situation includes determining whether a base station which transmits DSCH is a primary base station or not, number of base stations that transmits TFCI2, where the TFCI2 is information on the DSCH, setting a power offset according to a result of the determination, and transmitting the TFCI2 using the set power offset.