A method for sending and receiving multi-carrier information in a communication system supporting a multi-carrier includes sending by a base station system information to the terminal via a broadcast message, the system information regarding multi-carriers that the base station is able to support; receiving a unicast message from the terminal, the unicast message including information related to carriers that the terminal is able to support or prefers in the multi-carrier list included in the system information; and sending multi-carrier allocation information including a primary carrier and a second carrier that the terminal will use, to the terminal via a unicast message.