A service directory system, service registration and access method

The invention is applicable to the communications field and provides a service catalogue system and a service registration and visit method. The system comprises a service registration agent unit which receives and processes local service and roaming service registration requests or registration renewal requests in local service subnet, an assignment service information database which storages registration information or registration renewal information of local service that is registered in the local service subnet and actual location information of the roaming duplicate when the local service stays in the roaming state, a visit service information database which storages the registration information or registration renewal information of local service that is registered in the local service subnet and a service detection agent unit which receives and processes user service visit requests. The invention realizes the division of assignment service and roaming service and at the same time realizes the registration and visit of roaming service. Besides, multi-point registration of the same service and multi-point service registration information synchronous renewal are also realizedand service roaming access is supported.