The ethical review of clinical research on rare diseases is crucial in ensuring the scientific validity of the research and the rights and interests of the subjects. Starting from the definition of rare diseases， this paper analyzed the current situation of domestic and international regulations and ethical review in clinical research on rare diseases. It also explored the key elements of ethical review from the two dimensions of scientific and ethical aspects of clinical research， including research objectives， methods， risk and benefit assessment， researcher qualifications， research infrastructure， informed consent process， data security and privacy protection， and protection of vulnerable groups such as children. Regarding the ethical review of clinical research on rare diseases， strategies can be adopted such as strengthening the training of ethics review personnel， conducting multi-center collaborative reviews， and focusing on the long-term safety of trials， to improve the quality of ethical review， protect the safety of the subjects， and ensure the efficiency and quality of clinical research.