Provided is a method of cross-paging including transmitting mobile terminal location information from a mobile communication system to a heterogeneous mobile communication system after the mobile terminal location registration. The mobile communication system is then requested to page the mobile terminal according to the received information in the heterogeneous mobile communication system and, then the mobile terminal is paged. Further provided is a method of cross-paging that includes determining whether the mobile terminal has been location-registered in the mobile communication system or in the heterogeneous mobile communication system with reference to pre-registered mobile terminal location information when a mobile terminal paging request occurs in the heterogeneous mobile communication system. A cross-paging message is then transmitted from the heterogeneous mobile communication system to the mobile communication system if the mobile terminal has been location-registered in the mobile communication system and then the mobile terminal is paged.