Disclosed is a method for setting up a substituted ring back tone (RBT) provided from a predetermined communication provider, and more particularly, a method and system for recognizing a first substituted RBT of a first subscriber and setting up the first substituted RBT as a substituted RBT of a second subscriber, between subscribers of different communication providers. According to the present invention, it is possible to easily copy a substituted RBT from another user's substituted RBT and set up the same as a user's own substituted RBT. In this instance, the substituted RBT is provided according to a request for a call setup of a mobile terminal. Also, it is possible to set up a substituted RBT of a subscriber of a different communication provider as a user's substituted RBT, while not receiving predetermined information from the communication provider.