According to one embodiment of the present invention, a method for processing a notification message for applying a group policy to a notification subscription service in a wireless communication system is performed by a first M2M device, and comprises the steps of: receiving a plurality of notification messages; determining whether a group subscription ID matching with a group subscription ID pre-stored in the first M2M device is included in the plurality of received notification messages; indicating, by the group subscription ID, a group policy applied to the subscription service for the notification messages for member resources belonging to a specific group; and aggregating the notification messages in which the group subscription ID matching with the pre-stored group subscription ID is included, and applying, to the aggregated notification messages, the group policy corresponding to the group subscription ID.