OBJECTIVE： To investigate the effects of intensive treatment of Isophane protamine biosynthetic human insulin injection （premix 30R， called “Novolin 30R” for short） on blood glucose， HbA1c and islet B cell function of patients with primary type 2 diabetes. METHODS： 68 patients with primary type 2 diabetes were divided into observation group and control group by random number table method， with 34 cases in each group. Control group received acarbose+glimepiride orally；  observation group received Novolin 30R subcutaneously， and the dose and times of injection were adjusted according to blood glucose level. The target fasting blood glucose （FBG） and 2 h postprandial blood glucose （2 hPG） were 3.9-7.2 mmol/L and 7.8-10.0 mmol/L. FBG， 2 hPG， HbA1c， the time of blood glucose reaching the standard， BMI and islet B cell function were compared between 2 groups. RESULTS： FBG， 2 hPG， HbA1c and BMI of 2 groups had no statistical significance before treatment （P＞0.05）； compared to before treatment， FBG， 2 hPG and HbA1c of 2 groups were decreased significantly after treatment， and observation group were significantly lower than those of control group； the time of blood glucose reaching the standard was significantly shorter than control group， with statistical significance （P＜0.05）. There was no statistical significance in BMI between 2 groups before and after treatment （P＞0.05）. Before treatment， HOMA-IR， HOMA-B and I30/G30 of 2 groups had no statistical significance （P＞0.05）； compared to before treatment， HOMA-IR of 2 groups were decreased significantly， while HOMA-B and I30/G30 were increased significantly after treatment； the indexes of observation group was significantly better than that of control group with statistical significance （P＜0.05）. No obvious ADR was found in 2 groups. CONCLUSIONS： Intensive treatment of Novolin 30R can effectively reduce blood glucose and HbA1c levels of patients with primary type 2 diabetes， shorten the time of blood glucose reaching standard and improve islet B cell function with good safety.