Abstract: Postoperative complications are important indicators for evaluating surgical outcomes, and mortality and the incidence of various specific complications are often used to measure the efficacy of surgical and perioperative management strategies. With the progress of medical technology, there has been a dramatic decline in mortality and the incidence of complications. As a result, reporting and evaluation in the traditional methods no longer meets the actual needs of the world. There has arisen an urgent need for an instrument of standardized reporting and evaluation. The instrument should be aligned with the actual circumstances and should represent the patient’s overall burden of postoperative complications. We herein reviewed the latest research findings on Clavien-Dindo Classification (CDC) system and comprehensive complication index (CCI), two instruments of standardized reporting and evaluation of postoperative complications, and discussed the space for improvement and prospects of application of CDC and CCI.