The normal value of blood glucose two hours after meal should be <7.8mmol/L, which is regarded as normal postprandial blood glucose, not how much to how much. After a normal meal, blood glucose can reach a peak in 30 minutes to 1 hour, and then gradually decline, generally in 2 hours after the meal can gradually return to the normal level. The normal value of 2-hour postprandial blood glucose should be <7.8mmol/L. If fasting blood glucose <7.0mmol/L, but 2-hour postglucose load blood glucose ≧7.8mmol/L and <11.1mmol/L, it suggests that glucose tolerance is reduced. The 2-hour postprandial blood glucose is regarded as an important time point in the diagnosis and treatment of diabetes mellitus, and diabetic patients should pay attention to the daily monitoring of blood glucose. Seek medical attention when abnormal blood glucose levels are detected.