<p>An method for implementing CRBT, including: the MSC receives the call initiating from the calling party, obtains the CRBT information of the calling party which is the ring back tone service subscriber, and establishes the CRBT branch according to the CRBT information of the calling party. A system for implementing CRBT is also provided, thereby the CRBT can be send back to the user based on the need of the user with flexibility.</p>
