Method and system for virtual multicast networking, which can provide multicasting application service on non-multicast network that does not support multicast, are provided. A virtual multicast networking system for providing virtual multicast network on network environment where a multicast data source network to which multicast data source server is connected is linked through backbone network to non-multicast network that does not support multicast and to which a client is connected, the virtual multicast networking system includes: virtual multicast router system, included in the non-multicast network, for routing or relaying multicast data through tunnelling to multicast router or the nearest virtual multicast router system; multicast agent system, mounted on the client, for receiving the multicast data through tunnelling to the nearest virtual multicast router system, and transmitting the received multicast data to application program mounted on the client; and multicast management system, included in the multicast data source network, for managing the IP address of the virtual multicast router system and transmitting the IP address information of the virtual multicast router system to the virtual multicast router system or the multicast agent system.