DPP-4 inhibitors (dipeptidyl peptidase IV) inhibitors are a brand new class of drugs for the treatment of type 2 diabetes mellitus, which has been relatively widely used only in recent years, and its main mechanism of action is to enhance insulin secretion and inhibit glucagon secretion in a glucose concentration-dependent manner, improve glucose metabolism, reduce β-cell apoptosis, and promote the proliferative effects of β-cells. This drug has been clinically used in patients with type 2 diabetes mellitus to reduce glycated hemoglobin, fasting blood glucose, postprandial blood glucose levels, body weight and to reduce the occurrence of hypoglycemia and side effects. Therefore, DPP-4 inhibitors are gradually becoming an important choice for the treatment of type 2 diabetes. So should this drug, what are the need to pay attention to the problem or special aspects? Summarized as follows: 1, suitable for type 2 diabetes, not suitable for type 1 diabetes. 2.Only need to be taken orally once a day, not affected by meals. 3, single drug application can reduce glycated hemoglobin, combined with metformin to lower sugar effect is better; 4, alone application of hypoglycemia risk is very small, and combined with sulfonylurea, will increase the risk of hypoglycemia; 5, the effect on weight is neutral, generally does not increase weight.