A teleconferencing system making use of computers and network communication lets people participate in a conference without staying together. During the conference, participants communicate with one another through electronic devices such as terminal, mouse, . . . , etc, and network. In this paper, we present the constructing of a teleconferencing system based on a standard software system, X/Window System. It discusses an X-based system model for tools necessary in a teleconferencing system, then analyzes the concurrency controls and communication mechanisms among these tools. A prototype for text-based conference called CTUTC for chairperson-members is presented since X provides dynamic-window configuration. Our model provides a framework from which an iconic-based generating system is possibly built.