Disclosed are a method of generating and transmitting a ring back tone and a system thereof. The method of generating a ring back tone in a first terminal based on an internet protocol comprises identifying a type of a network to which a second terminal requesting a call setup belongs, generating ring back tone data to be transmitted to the second terminal according to the type of the network, inserting the ring back tone data into a response message to the call setup, and transmitting the inserted response message to the second terminal.