A method of configuring a carrier in a multi-carrier system by a User Equipment (UE) includes receiving, from the first cell, barred-cell information instructing a first cell to be designated as a barred-cell, receiving, from a second cell corresponding to a second carrier, carrier configuration information, instructing a configuration of a first carrier corresponding to the first cell, and configuring a selected carrier based on either the designation of the barred-cell or the carrier configuration information.