Substitutable local domain management system and method for substituting the system

A substitutable local domain management system and a method thereof are provided to manage a domain through current domain management information after changing a domain management system and substitute the domain management system conveniently by keeping relation between a present domain member device and domain after changing the domain management system. An assignment requestor(220) requests a DA(Domain Authority) to assign a domain management system to a user domain. A UDMS(User Domain Management State) information receiver(240) receives UDMS information for the user domain from the DA when the user domain is assigned. A user domain manager(250) manages the user domain based on the received UDMS information. The UDMS information is the information stored to the DA by other domain management systems previously managing the user domain. A registration requestor(210) transmits a request for registering the domain management system to the DA. The assignment requestor requests the DA to assign the domain management system to the user domain when the domain management system is registered to the DA. The registration requestor transmits user credential including a user ID/password to the DA to authenticate a user.