Risk stratifications are valuable aids for stratifying patients by disease severity, driving informed clinical decisions, because they allow the selection of the most appropriate strategy of treatment based on the patient's individual characteristics. The clinical algorithms help patients and their families to get a better understanding of issues relevant to treatment strategies and subsequent risks as part of the process to obtain informed consent. The current risk stratifications of coronary artery bypass grafting included the Society of Thoracic Surgeons Score, the European System for Cardiac Operative Risk Evaluation, SinoSystem for Coronary Operative Risk Evaluation. This review focuses on the progress of risk stratifications of coronary artery bypass grafting for patients undergoing cardiac surgery.