The present invention provides an apparatus and method for controlling transmission powers of R-CQICH (reverse-channel quality indicator channel) and R-ACKCH (reverse-acknowledgment channel) independently. The present invention includes the steps of receiving a first parameter corresponding to the R-CQICH and a second parameter corresponding to the R-ACKCH from a base station via an overhead message and independently determining transmission powers of the R-CQICH and the R-ACKCH using the first and second parameters.