A handover method of a user equipment supporting carrier aggregation, comprising: transmitting, to a source node base, NodeB, measurement result of a channel quality with respect to each of component carriers(CCs) of the source NodeB and a target NodeB; receiving, from the source NodeB, a handover execution command, wherein the handover execution command comprises configuration information about a primary component carrier and one or more secondary component carriers, C-RNTI of the target NodeB, and security key information; configuring the primary component carrier and the one or more secondary component carriers according to the configuration information; and attempting an access to the target NodeB and an uplink synchronization establishment; performing handover to establish connection with the target NodeB, wherein the configured one or more secondary component carriers are in a deactivated state during the handover; receiving, from the target NodeB, a response with respect to a resource assignment for an uplink access attempt, a synchronization establishment complete, and activation control message for activating the one or more secondary component carriers; and transmitting a handover complete report message to the target NodeB, wherein the target NodeB receiving a handover request from the source NodeB determines the primary component carrier and the one or more secondary component carriers in the target NodeB based on information of the user equipment, channel quality measurement result with respect to CCs of the target NodeB, and a load status including control signaling with respect to each of the CCs of the target NodeB, and wherein the target NodeB performs an activation procedure of the one or more secondary component carriers by transmitting the activation control message after the connection with the user equipment is established. transmitting, to a source node base, NodeB, measurement result of a channel quality with respect to each of component carriers(CCs) of the source NodeB and a target NodeB; receiving, from the source NodeB, a handover execution command, wherein the handover execution command comprises configuration information about a primary component carrier and one or more secondary component carriers, C-RNTI of the target NodeB, and security key information; configuring the primary component carrier and the one or more secondary component carriers according to the configuration information; and attempting an access to the target NodeB and an uplink synchronization establishment; performing handover to establish connection with the target NodeB, wherein the configured one or more secondary component carriers are in a deactivated state during the handover; receiving, from the target NodeB, a response with respect to a resource assignment for an uplink access attempt, a synchronization establishment complete, and activation control message for activating the one or more secondary component carriers; and transmitting a handover complete report message to the target NodeB, wherein the target NodeB receiving a handover request from the source NodeB determines the primary component carrier and the one or more secondary component carriers in the target NodeB based on information of the user equipment, channel quality measurement result with respect to CCs of the target NodeB, and a load status including control signaling with respect to each of the CCs of the target NodeB, and wherein the target NodeB performs an activation procedure of the one or more secondary component carriers by transmitting the activation control message after the connection with the user equipment is established. <EOS>