The present invention relates to a wireless communication system. More particularly, the present invention relates to a method and an apparatus for receiving control information in a wireless communication system in which a first carrier type and a second carrier type are aggregated. The method comprises a step of receiving grant information for signal transmission on the second carrier type, wherein the grant information is received through the second carrier type if the grant information includes a first downlink control information (DCI) format, wherein the grant information is received through the first carrier type if the grant information includes a second DCI format.