The present invention provides a method for receiving acknowledgement/not-acknowledgement (ACK/NACK) of a terminal in a wireless communication system. The method transmits uplink data through an uplink data channel and receives ACK/NACK for the uplink data. The uplink data channel is transmitted through aggregated carriers and the aggregated carriers include a first band recognizable to first and second type terminals and a second band recognizable only to the second type terminal.