The present invention provides a method and system for preventing MAC address learning in Provider Backbone Bridge Network (PBBN). In one embodiment, this is accomplished by receiving data frames from at least one operator/client at the first PBB network which has to be communicating to the second PBB network, adding forward path learning information from the received data frames in the first PBB network and translating backbone MAC source address of the received data frame at the first PBB network by replacing the backbone MAC source address with a BEB backbone MAC address, thereby preventing of backbone MAC address learning of the first PBB network in the second PBB network.