Abstract: The present invention discloses a PTT service system and method thereof. The system includes a user terminal equipment, an application server, a control equipment and a gateway equipment, in which, the user terminal equipment connects with said application server, control equipment and gateway equipment by access network; the application server connects with said access network and control equipment for building lists of users groups and relating information and storing and managing them; the control equipment provides establishment of signaling messages for the user terminal equipment, distributes them to other terminal equipment within group, and controls the gateway equipment; the gateway equipment sets up media stream with the user terminal equipment based on signaling of the control equipment, and distributes the media stream sent by users having a right of speaking to other users within the group.