Two-hour postprandial blood glucose is an important indicator in the diagnosis of diabetes mellitus and blood glucose control index, but its normal value is individual differences. In normal healthy people, the normal value of two-hour postprandial blood glucose should be less than 7.8mmol/L. If the two-hour postprandial blood glucose is greater than or equal to 7.8mmol/L but less than 11.1mmol/L, then it is an abnormal glucose tolerance; if the two-hour postprandial blood glucose is greater than or equal to 11.1mmol/L, then diabetes mellitus can be diagnosed. For diabetic patients, the control value of two hours after meal should be different according to the patient’s age and physical condition. If the patient is young and in high physical condition, the two-hour postprandial blood glucose should be controlled to the normal level, i.e., less than 7.8mmol/L. However, with the increase of age, this index can be slowly relaxed, and if the patient’s physical condition is poor, this index can also be relaxed, such as for the elderly over 80 years old or people with serious complications or comorbidities, the two-hour postprandial glucose of 10-15mmol/L can be regarded as a good indicator for diabetic patients. 15mmol/L are acceptable. For gestational diabetics, it is recommended that the two-hour postprandial blood glucose be less than 6.7mmol/L. Therefore, the normal value of blood glucose two hours after meal is less than 7.8mmol/L, but the range may vary according to the population, age and physical condition.