Objective To evaluate the advantages of blood glucose control while insulin glargine are used for type 2 diabetic patients with upper gastrointestinal bleeding in acute phase, by means of analyzing its biological characteristics. Methods fortysix cases of upper gastrointestinal bleeding with diabetes mellitus were randomly divided into A and B groups, and 23 cases involved in each group. For group A, the blood glucose was control by intravenous glucose added the shortacting insulin and subcutaneous insulin glargin at 8:00am, adjusting the dosage according to fasting blood glucose. For B group, the blood glucose was control only by intravenous glucose added the shortacting insulin, which dosage was adjusted according to the values of random blood glucose. The random blood sugar control targets in both groups were in 10.0mmol/L. Additionally the ways of hematischesis treatment were same in two groups. The advantage of subcutaneous insulin glargine  was estimated by observing following indexes of patients, such as black excrement, samples from stomach, hypoglycemia symptom, the daily average of blood sugar, insulin amount used each day, and occult blood clearance time. Results Comparing between A and B groups, the observation result suggested that the type 2 diabetic patients with upper gastrointestinal bleeding, who were treated by subcutaneous insulin glargine, seldom occur hypoglycemia symptom and used fewer small dosage of insulin. The , that stems from insulin glargine’s good biological characteristics.