Apparatus and method for controlling outer loop power

A communication system having multiple channels is disclosed. An apparatus for controlling outer loop power in the communication system having the multiple channels includes a step adjustment unit for re-setting height of a step size for power controlling with reference to a CRC result, when the CRC result is received from a base station; and a power controller for determining a target signal to interference ratio (SIR) with reference to the CRC result and the re-set step size information, and transmitting the determined target SIR to the base station. Power controlling operation can be more effectively performed in the communication system having the multiple channels.