The present invention relates to a method for adding background sound to mobile communication talking. In the method of the present invention, a subscriber may dial additionally a background sound service number at the time of calling the a called party to make a mobile communication exchange, on the basis of the additionally-dialed number, add a talking link of a third party provided by the background sound system to establish a three-party talking at the time of establishing a talking link between a calling mobile communication terminal and a called mobile communication terminal. Thus, the calling and called parties can have a background sound service during the talking. According to the present invention, the calling subscribers are enabled to readily add background sound to relevant talking with the called parties through additionally dialing background sound service numbers and therefore, new telecommunications valued-added services may be added in existing mobile communication networks, making the talking between the calling and called parties more interesting and humanized.