In this study, using the HL7 protocol, we developed patient management system gateway which is composed of 2 parts; message transferring-receiving and sentcncc generating-parsing part. To make the gateway more transplantable, it was developed on the PC operated with Windows OS. To make the gateway more productive, it was developed with Visual Basic 6.0. The database was built into MS SQL. Server which is most optimized on MS Windows NT system environment. This gateway system has the advantage of easy data-exchange capability between the patient management systems of medical facility and the messages transferred can he managed systematically and he transplanted easily into PC base hospital information system.