Provided is a paging method and apparatus considering a carrier aggregation (CA) environment in a mobile communication system. A paging method of a user equipment may include: selecting a component carrier (CC) set of the user equipment by selecting a CC for each component carrier element (CCE); receiving, from an evolved Node-B (eNB), a paging message containing a CC set; setting up a connection with the eNB through the CC set of the user equipment when the received CC set is the same as the CC set of the user equipment, or when all the CCs are included in the received CC set; and changing the CC set of the user equipment to the received CC set and setting up the connection with the eNB through the changed CC set when the received CC set is different from the CC set of the user equipment.