The present invention relates to an initial access based control method between a personal subscriber station and a radio access station in a mobile communication system. The present invention includes: a) selecting an initial access method corresponding to a first field value of a first parameter included in a first downlink channel descript message received from the radio access station; b) generating a first ranging request message corresponding to the initial access method; and c) transmitting the first ranging request message to the radio access station. The present invention guarantees mutual compatibility with the existing broadband wireless access system and realizes various initial access methods between the subscriber station and the radio access station.