Objective: This study was designed to evaluate the clinical efficacy of intensive insulin therapy for patients newly diagnosed with type 2 diabetes. Methods: A total of 219 patients newly diagnosed with type 2 diabetes were randomly assigned into insulin group (n = 55), gliclazide group (n = 52), metformin group (n = 55) and pioglitazone group (n = 57). On the basis of diet and physical interventions, patients in the insulin group received intensive insulin therapy. Those in other three groups were given oral intake of medication. All treatment schemes endured for 12 weeks. A variety of indexes including fasting blood-glucose (FPG), FPG at 2 h after diet (FPG 2 h), hemoglobin A1 c (HbAlc), area under the curve (AUC) for insulin (insulin AUC) after glucose load, C-peptide AUC after glucose load (C-peptide AUC), changes in insulin secretion index (Homa-beta) and insulin resistance index(Homa-IR) were accurately measured and statistically among different groups. Results: The insulin AUC at 0-30 min, C-peptide AUC at 0-30 min and Homa-beta in the insulin group were equally significantly higher compared with those levels in the other three groups. In addition, the level of Homa-IR in the insulin, metformin and pioglitazone groups were all significantly reduced compared with the values prior to respective treatment (all P < 0.05). Conclusion: Compared with oral administration of hypoglycemic drugs, intensive insulin therapy is able to better improve pancreatic beta cell function and insulin resistance for newly-diagnosed type 2 diabetes patients.