The present invention relates to a method for performing a ranging operation according to the priority order in a mobile communication system using a BWA (Broadcast Wireless Access) scheme. The method according to the invention for performing a range operation by a subscriber terminal in a mobile communication system using the BWA (Broadcast Wireless Access) scheme comprises steps of: receiving backoff domains having the start and end values of the backoff corresponding to each ranging operation, the backoff domains being determined from a base station according to the priority order of the ranging operations between the base station and subscriber terminals; performing a ranging operation and, if it is determined that the step of performing the ranging operation fails, selecting backoff domains among the received backoff domains according to the priority order of the performed ranging operations; and, re-performing the ranging operation according to the selected backoff domains.