Abstract: To support large-scale fleets to communicate with multiple monitoring centers using both short message service and general packet radio service, a communication server was designed based on the careful study of the communication model. The server implemented most critical communication functions such as packet switching, packet broadcasting, protocols transferring, and etc. The thought of sacrificing memory for speed was sufficiently deployed in data structure design, and multithread, message and component technologies were used in realization to improve the efficiency of the server. The test results show that the server works effective and steady in large -scale fleets monitoring systems.