Discharge summary is one of important clinical data in medical records, and it concisely summarizes the patient’s stay during hospitalization. In this thesis, we use web-based architecture in developing a new discharge summary system of National Taiwan University Hospital, and improve the traditional client/sever architecture of old system. This thesis introduces the design considerations and implementation level in detail, including summary search and query, model and phrase quoted, summary check list, major editing blocks and other functionalities. In addition, the new system incorporates several novel technologies to improve the usability and interactivity. Finally, we discuss a comparison between the client/sever and web-based system, assess the quality of new technology, survey the completeness of new system as well as the actual user test and user satisfaction.