A method of providing neighbor base station information via a mobile subscriber station in a broadband wireless access system is disclosed. In providing neighbor base station information (S316) to a serving base station from a mobile subscriber station in a broadband wireless access system, the present invention includes the steps of performing a scanning and a synchronization (S312, S313) on a mobile base station based on information provided from the serving base station (S311) and transmitting the neighbor base station information acquired from the scanning and the synchronization to the serving base station (S316) regardless of a presence or non-presence of a request from the serving base station. Accordingly, the present invention can efficiently transmit the neighbor base station signal intensity and frame information acquired by the mobile subscriber station.