In a radio resources management method for a Wireless Local Loop (WLL) system, the compatibility of a radio environment can be judged by setting and storing information of a home base station, of a WLL subscriber terminal, and comparing the stored information with information of a base station currently relaying communications with the WLL subscriber terminal. Compatibility of the radio environment can also be judged by comparing the reception time intervals of a power ON/OFF message, position registration request message, or call processing request message with a reference time, at certain audit cycles.