This study was performed to develop the basic technique for standardization that will be used in the medical environment. The following paper describes the design and implementation of a software framework that could be used to construct an HL7 message server. HL7 message server is combined with existing HIS and generates the corresponding HL7 messages automatically whenever the predefined events occur. We developed HL7 message server modules which can automatically link patient data to the appropriate message component in order to populate ADT and ORU messages. The key modules are UIT monitor, message generator and TCP/IP connection module. UIT is designed to integrate all data items needed to create a message in this HIS database table. The UIT monitor module checks regularly the occurrences of predefined events in HIS. The message generator module links the UIT data to the appropriate message generating functions to create a message. And the TCP/IP connection module works as a socket module for the stable network connection. The prototype of HL7 message server showed the performance of creating 100 messages in a second. This evaluation result confirmed that our HL7 message server presents a promising model for the incorporation of HL7 standard into existing Korean HIS.