Many groupware systems have been used for communication between Personal Computers (PCs) in companies. However, recently, the demands for groupware systems are growing. Especially, by the spread of mobile phone users and systems, new mobile phone groupware systems are needed. In the groupware systems, the location information function which is used to know the location of the group members is a very important function for smoothing the group activities. In this paper, we propose a mobile phone groupware system using the location information function. By resolving some problems of location information function of Devora system, we improve the performance of the proposed mobile phone groupware system. The evaluation results show the our system has a smooth operation and the communication cost is decreased.