Currently, many computer systems are used in many areas of medicine including radiation oncology. For the most part, the computer system has proved to be useful in radiotherapeutic planning and dose calculation. There has been attempts to develop computer system including information management of patients, patient tracing, and office automation in radiation oncology department. But some of these available commercial systems have shortcomings. We developed a management system of patients in our radiation oncology department that integrated most of items for the evaluation of patents. In particular, the data were stored in a natural language (noncoded) and made themselves easily understandable by all clinical groups. In addition, the data could be isolated in files from which the computer could generate graphs and static data by the use of some simple commands. The system provided us with not only the functions of case review but functions of preparation of conferences, lectures and resident teaching.