Postprandial blood glucose refers to 2-hour postprandial blood glucose, starting from the first bite of the meal, and the normal value of 2-hour postprandial blood glucose is less than 7.8 mmol/L. When the two-hour postprandial blood glucose is between 7.8-11.1 mmol/L it is considered to be an abnormality of glucose tolerance, which is a stage of impaired glucose regulation, and belongs to the pre-diabetic stage. When the two-hour postprandial blood glucose is greater than 11.1mmol/L then diabetes can be diagnosed and blood glucose needs to be rechecked at different times to confirm the diagnosis of diabetes. The normal range of blood glucose two hours after three meals is the same, that is, the normal value of blood glucose two hours after lunch is less than 7.8 mmol/L. When the blood glucose two hours after any meal is higher than 7.8 mmol/L, it is necessary to review the fasting and postprandial blood glucose, glycated hemoglobin, and to treat diabetes with diet and exercise. When the diet and exercise treatment can not make the blood glucose standard, need to according to the blood glucose situation under the guidance of the doctor to be treated with hypoglycemic drugs.