Method of providing alarm service upon movement out of safety zone

Disclosed herein is a method of providing alarm service upon movement out of a safety zone in a mobile communication network. The method is implemented in such a way as to acquire past location registration information for a ward's mobile terminal designated by a subscriber (guardian), the past location registration information being base station identifiers associated with base stations at which the past locations of the ward's mobile terminal has previously been registered, store the acquired past location registration information to a My Base Station DB allocated to the ward, check base station information, associated with a base station at which the current location of the ward's mobile terminal has been registered, at the time of an observation request, determine whether base station information has been stored in the My Base Station DB, detect movement out of the safety zone when the base station information has not been stored in the My Base Station DB, and notify the subscriber of movement out of the safety zone.