Provided is an apparatus and method for performing activation/deactivation of a serving cell in a wireless communication system supporting dual connectivity. The method for performing activation/deactivation of serving cell by a user equipment in a wireless communication system includes configuring a dual connectivity with at least two different base stations based on dual connectivity configuration information received through RRC (Radio Resource Control) message from a base station, receiving activation/deactivation information about secondary serving cell configured for the UE from each of two different base stations, and selectively applying the activation/deactivation information about the secondary serving cell configured for the UE based on information including the secondary serving cell provided by the base station or information about the base station providing the secondary serving cell configured for the UE.