A mobile station supporting selective transmit diversity (STD) efficiently transmits forward channel status information to a base station in a 1xEV-DV mobile communication system. The mobile station receives signals transmitted from the base station through a plurality of transmission antennas, measures signal strengths of the received signals, compares the measured signal strengths after compensating for a transmission power difference between the transmission antennas, and selects a transmission antenna having the highest signal strength. The mobile station transmits forward channel status information indicating measured signal strength for a signal transmitted from the selected transmission antenna to the base station along with antenna selection information indicating the selected transmission antenna. The forward channel status information includes absolute status information representing measured signal strength for a transmission antenna selected at a current time interval, or relative status information representing a result obtained by comparing the measured signal strength for the transmission antenna selected at the current time interval with measured signal strength for a transmission antenna selected at a previous time interval.