the Efficacy of Acarbose and Metformin on Blood Glucose Fluctuation When Combined With Premix Insulin

Inclusion Criteria: * Diagnosed T2DM patients (WHO, 1999). * Premix Insulin therapy for more than 3 months, the daily dosage of insulin \>20IU and \<1IU/kg * 30 ≤Age ≤ 70 years old, male or female * 7.0 ≤ HbA1c ≤10.0% * 18.5≤ BMI ≤ 35 kg/m2 * Written Informed consent Exclusion Criteria: * Subject with type 1 diabetes or gestational diabetes mellitus and other specific types DM * Those who can not tolerate AGI or who is suffering GI disease * Metformin contradiction * Concomitant 2 oral anti-diabetes medicine, or 1 OAD with maximum dose * Subject with repeated severe hypoglycemia and/or unawareness of hypoglycemia * Known or suspected allergy to trial product(s) or related products * Females of child bearing potential who are pregnant, breast-feeding or have the intention of becoming pregnant or not using adequate contraceptive methods throughout the trial * Impaired liver function, * Any other clinically significant condition or major systemic diseases, including serious coronary heart disease, cardiovascular disease, cancer, TB, acute infection * Uncontrolled hypertension * Concomitant treatment which influences blood glucose * Impaired renal function