We can study medical ethics based on three main subjects of ethics in education, ethics in research and clinical ethics at the beginning, during and at the end of life, and after death. Medical Ethics deals with all aspects of medical sciences, however, in contrast with the medical ethics in previous centuries which were exclusively concerned with the physician-patient relationship, since 1970s with the rapidly developing biomedical technology, there appeared new challenges in medical practice that are the subjects of medical ethics today. As a main sub discipline of medical ethics, clinical ethics deals with the ethical rules of the physician-patient relationship and the new problems such as clinical trials, genetics, organ transplantation, euthanasia, physical examination, fair allocation of scarce health resources, expensive surgeries, medically-assisted fertilizations and access of the patient to the necessary information regarding the diagnosis and treatment. In this article, the author tries to study parameters of clinical ethics, the development of clinical ethics, strategic planning for teaching clinical ethics, care- based ethics and the role of ethical counseling in health care system as the main subjects in medical ethics.