An outer-loop power control method and a communication apparatus having an outer-loop power control function for increasing target SIR if an error is detected in a block-error observation interval and decreasing target SIR if not a single error is detected in the block-error observation interval. At least one of the block-error observation interval, an incrementing step for when target SIR is increased and a decrementing step for when target SIR is decreased is varied based upon the number of erroneous blocks among error-detecting blocks contained in a transmission time interval TTI.