A method for operating a femtocell in a wireless communication system comprises the steps of: triggering the switching from the operation mode for providing a service to closed subscriber group (CSG) terminals which belong to a specific terminal group and to non-CSG terminals which do not belong to the specific terminal group, to the operation mode for providing the service only to said CSG terminals; and commanding said non-CSG terminals to change the operation mode, and carrying out a handover. The method of the present invention improves efficiency of femtocell operation, and reduces restrictions on terminals disposed in the vicinity of the femtocell. The method of the present invention can utilize the unused frequency range of the femtocell, thereby providing a service with a high data ratio.