Medicine in the twenty-first century will be different from the medicine of today. Recent changes in medical environment, such as changes in disease and mortality pattern and rapid increase in medical knowledge, require change and adaptation of medical education. The task of medical education is to help people entering medicine to prepare to meet their professional obligations in this new context. So we tried to join Problem-base learning(PBL), which challenges students to be more actively involved in defining what they learn and how they learn, and Computer-assisted learning(CAL), which uses multimedia and medical informatics as learning tools. Finally we developed Problem-oriented medical education program using the Internet. First, using simulated patient cases, we built clinical database with patients' history, physical examinations, and various laboratory findings. To provide PBL program through the Internet, we constructed client-server system using IJS(Internet Information Server) on Windows-NT settings, and made user-friendly dynamic interface with HTML, JAVA, JAVA Script and so on. PBL on the Web will make students learn effectively and actively, and offer vivid multimedia environment for medical education. We expect this PBL program to be used as an effective learning tool for residents or doctors as well as for medical students in the near future. The Internet