This research presents development of real-time service primitive in MHS(Message Hanling system) supporting desk-top conferencing system. Desk-top conferencing system is one of the real-time GC(Group Communication) services. The complexity of modem society has led to the consequent need for real-time GC between a number of people in order to jointly handle tasks in business, government and other forms of organization. Despite the many different form of desk-top conferencing systems developed to date, there are still few systems in widespred no. One of the biggest hurdle preventing the widespred adoption of real-time GC is the lack of agreement on user-friendly interchange environments. In distributed office environments, the MHS is one of the most widely used service for information interchange. It is a standard of electronic mail system which is concerned mostly with asynchronous exchange of short notes. It is clear that additional functions on MHS are necessary in order to allow users to properly process their real-time group messages and provide them with important facilities as a communication infrastructure for real-time GC.