Preoperative fasting may results in discomfort feelings, such as hunger, thirst and anxiety of patients, or cause severely blood pressure variation and postoperative insulin resistance, which may increase the ratio of complication happening. Based on latest researches, preoperative oral carbohydrate solution (POC), can ameliorate complications mentioned above without increasing any risk of surgeries or anesthesia. However, there is no definite guidance for standardizing the clinical use. This review aims to discuss the development of POC and current clinical application, focusing on not only the benefits and mechanism of POC, such as alleviating patients' negative nitrogen balance, remitting postoperative insulin resistance and improving patients' subjective feelings, but also the safety. We hope this review provides theoretical basis for the wide POC using in clinical practice.