Method and device for determining multicast group data

The invention discloses a method and device for determining multicast group data, and relates to the field of information technology, and by means of the method and device, the utilization rate of multicast traffic can be increased. According to the method, the method for determining the multicast group data is applied to a multicast virtual private network, the multicast virtual private network comprises a rendezvous point (RP), a provider edge (PE) and a user device, the PE corresponds to the user device, the RP communicates with the PE, and the PE communicates with the user device; firstly, a request message sent by the user device is received by the PE, then, the multicast group data required by the user device are determined according to the address of the multicast group data required by the user device, and finally, the RP sends the multicast group data required by the user device to the user device through the PE. The method and device for determining the multicast group data are suitable for the situation that a multicast source sends the multicast data to the user device.