Diabetic patients currently commonly used four oral hypoglycemic drugs include the following: First, metformin, metformin for diabetic patients is the drug of choice, to lower blood sugar, improve insulin sensitivity, weight control role is relatively significant. Sulfonylurea hypoglycemic drugs, mainly refers to glipizide, glipizide, glimepiride, these drugs can promote the secretion of endogenous insulin, has a significant role in reducing fasting or postprandial blood sugar, but easily lead to hypoglycemia. Insulin sensitizers, including pioglitazone and rosiglitazone, can lower blood glucose mainly by increasing insulin sensitivity. These drugs mainly inhibit the absorption of carbohydrates in the gastrointestinal tract to lower the blood glucose 2 hours after meal, and the effect on fasting blood glucose is not very obvious.