A method of switching a radio resource mode allocated to a mobile station in a wireless access system is disclosed. The method for switching the radio-resource mode allocated to the mobile station in the wireless access system includes, transmitting information of a second radio-resource mode to a base station, thereby requesting a switching from a first radio-resource mode allocated to the mobile station to the second radio-resource mode, and re-requesting the switching of the radio-resource mode using a high-speed feedback channel, if a message approving the switching of the radio-resource mode is not received within a predetermined time. So, a variety of problems caused by inconsistency in operation mode between a mobile station receiving no control messages and the base station can be solved.