Abstract： Hyperglycemia can result in severe adverse effects on the body.The mortality and morbidity of surgery are increased significantly in diabetic patients.The surgical stressrelated hyperglycemia and insulin resistance can also produce the same adverse consequences.The metabolic state of the surgical patients,anesthesia method,glucose infusion,stressinduced neuroendocrine responses and insulin resistance can affect the perioperative blood glucose levels,resulting in poor clinical outcomes.The relationship between tight glycemic control and reducing post-operative mortality and morbidity is not clear.It's necessary to control blood sugar level during the perioperative period but the ideal state of glycemic control still needs a mult-center clinical trial evidence.It is generally believed that perioperative blood glucose level should be controled below 10 mmol/L.The efficacy and safety of tight glycemic control needs further study.