Abstract: Disclosed is a telephone service system using a VoIP based on a network, which, after globalizing VoIP numbers to be sold to individuals or companies and generating a unified system, starts VoIP numbering services and sales services, confirms whether a VoIP number of a party user, a general PSTN number(or identification number), or a VoIP number a different company provides is inputted from a specific user terminal for a telephone service wit the party user, routes the VoIP number of the party user to a communication center of a corresponding country(area) or performs call switching of the VoIP number to meet a VoIP number system a different company provides, and performs the telephone service through the corresponding country.