[Protection of human subjects in medical research: from the viewpoint of historical development of ethical regulations].

Recent clinical research is conducted based on bioethical consideration of human subjects. The Ethical Guidelines for Clinical Studies (EGCS) form the standard for this 'subject protection'. In current clinical research, consideration of subject rights and life is held more important than the scientific and social value of the research. We describe herein the major revisions and history of ethical considerations leading up to implementation of the revised EGCS on April 1, 2009. The obligations of clinical researchers regarding ethical studies and training and enrollment in insurance for subject compensation have been added to these latest guidelines. The role of ethics review boards, which supervise whether clinical researchers are actively performing subject protection, is also becoming extremely important.