The target of blood glucose control for diabetic patients varies slightly according to the patient’s age, duration of diabetes, complications and life expectancy, and is divided into the following cases: First, most patients should achieve fasting blood glucose less than 7.0 mmol/L, non-fasting blood glucose less than 4.0 mmol/L and glycated hemoglobin less than 7%. Second, if the patient is old, combined with a variety of complications and frequent hypoglycemia, the target can be relaxed appropriately, with fasting blood glucose less than 8.0mmol/L and non-fasting blood glucose less than 11.1mmol/L. Third, if life expectancy is very limited, life cannot be taken care of by oneself, and blood sugar cannot be monitored, etc., fasting blood sugar of 10.0mmol/L and non-fasting blood sugar of no more than 13.9mmol/L can be maintained, in order to prevent acute metabolic disorders. Fourth, the goal of gestational diabetes control is fasting blood sugar lower than 5.3mmol/L, one hour after meal blood sugar lower than 7.8mmol/L, two hours after meal blood sugar lower than 6.7mmol/L.