Objective:To describe the current status and efficacy of additional acarbose combined with insulin therapy in adult patients with type 1 diabetes mellitus (T1DM) .Methods:Adult T1DM patients with acarbose combined with insulin (acarbose group) or insulin alone (insulin group), age≥18 years and disease course≥1 year, who were registered in the T1DM Translational Medicine Research Project of Guangdong Province from June 2011 to December 2014 were enrolled in the study. The hemoglobin A1c (HbA 1c), body weight, body mass index (BMI), waist-to-hip ratio (WHR), insulin dosage and hypoglycemia of acarbose group and insulin group after 1 year were compared. Results:A total of 717 adult patients with T1DM were included (62 cases in acarbose group and 655 cases in insulin group). At the time of enrollment, the onset age of acarbose group was higher than that of insulin group [(31.1±12.3)years vs (27.4±12.4)years, P=0.019]; There were no significant differences in gender, age, course of disease, body weight, BMI, WHR, proportion of carbohydrate heat ≥50%, proportion of exercise time ≥150 min per week, HbA 1c, dosage of insulin, occurence of hypoglycemia and proportion of patients with dyslipidemia between the 2 groups (all P>0.05). After 1 year of follow-up, the HbA 1c in acarbose and insulin group decreased from baseline ( P=0.014, P<0.001), the body weight and BMI increased from baseline (all P<0.05), but WHR, insulin dosage and hypoglycemia occurrence were not statistically significant between the two groups (all P>0.05). After 1 year of follow-up, there were no significant difference in changes of HbA 1c, body weight, BMI, WHR, insulin dosage and hypoglycemia occurrence in acarbose group compared with insulin group from baseline (all P>0.05). Conclusions:In the clinical practice of T1DM treatment, acarbose is used more frequently in patients with a slightly older age of onset. Treatment of T1DM with insulin combined with acarbose did not increase the incidence of hypoglycemia, and no benefit was observed in improving HbA 1c, maintaining body weight, and reducing insulin use.