Disclosed is a method of operating a femto base station (BS) in a wireless communication system, the method comprising: receiving an access request comprising a closed subscriber group (CSG) identifier (ID) from user equipment (UE); determining a number N of UE accessing the femto BS; ascertaining an access type to determine whether the UE is a CSG UE or a non-CSG UE of the femto BS on the basis of the CSG ID of the UE; and determining whether to admit access of the UE on the basis of the access type, the N and access admittable information, the access admittable information comprising UCSG, i.e., a maximum number of CSG UE of which access is admitted; UALL, i.e., a maximum number of non-CSG UE of which access is admitted; and UMAX, i.e., a maximum number of UE of which access is admitted.