Disclosed is a method and device for requesting and reporting channel quality information in a mobile communication system. A base station a locates a dedicated feedback channel for channel quality information report to an uplink radio resource, transmits the allocation information to subscriber stations, and generates a CQI report message to request channel quality information from the subscriber stations. The subscriber stations receive the CQI report message from the base station, measures a radio channel quality for communication with the base station, generates channel quality information, generates a CQI response message including the channel quality information, and transmit—the CQI response message to the base station through a dedicates feedback channel designated in the allocation information.