An apparatus and a method for managing an access mode of an NB in a wireless communication system. The method includes receiving, from a first NB, a request to change the access mode of the second NB from a first mode into a second mode; determining, by the CN, to change the access mode of the second NB into the second mode; transmitting, to the second NB, a request message requesting to change the access mode of the second NB; and receiving, from the second NB, a response message informing of an access mode control result. If the first mode allows access only to terminals having a registration in the second NB, and the second mode allows access to terminals, the second NB further grants access to at least one terminal not registered in the second NB, after changing the access mode.