In a radio access system for supporting multi-radio access technology (RAT), the present invention provides a method for allowing a terminal to transmit and receive data with a first base station for supporting a first RAT and a second base station for supporting a second RAT, and the method comprises the steps of: receiving, from said first base station, a first message which indicates scanning execution for said second base station; allowing said first message to include control information which is necessary for the scanning execution of said second base station, and executing the scanning for said second base station on the basis of said control information; and transmitting, to said first base station, a multi-RAT scan report message which contains the result of the scanning execution for said second base station.