In general, hospital information systems are operated independently of each other. We propose a next-generation hospital information system (HIS) based on the HL7 clinical document architecture (CDA) including also an electronic health record (EHR) and a clinical data repository (CDR) to enable the sharing of medical information among health and medical institutions. We designed an XML schema through which an effective clinical document was generated from the HIS after defining the item regulations and the templates for the release form and radiation interpretation form. The schema was analyzed according to the HL7 reference information model, and HL7 V2.4 was used as the transmission protocol. In addition to proposing a new HIS, we attempted to define the CDA of a release form and create a generation, saving, and control system for the release form based on that definition, the first such undertaking in Korea.