〔Abstract〕 Objective To evaluate the efficacy and safety of basal insulin therapy at a higher initial dose (0.4 U·kg-1) in newly diagnosed adult overweight and obese patients with type 2 diabetes mellitus (T2DM). Methods 66 Newly diagnosed T2DM patients (body mass index ≥ 24 kg/m2 ) were randomized to a higher (0.4 U·kg-1) or standard (0.2 U·kg-1) initial dose of insulin glargine 100 U/m, combined with metformin. Within 7 days of treatment, the dose of insulin in both groups did not increase, but could be reduced according to the following criteria: fasting blood glucose (FBG) 4.4-5.7 mmol·L-1, insulin minus 2U; FBG ≤ 4.4 mmol·L-1, insulin minus 4U. After 7 days, the dose of insulin was adjusted according to the unified standard. The evaluation indexes were the time needed to achieve FBG targets, the rate of reaching FBG targets and the occurrence of hypoglycemia within 7 days of treatment. Results The time to achieve FBG targets of ≤ 5.7 and ≤ 6.1 mmol·L-1 was shorter in the higher versus the standard insulin dose group (5.62 ± 2.60d and 4.74 ± 2.41d, respectively), all with significant statistical differences (P < 0.05). The glycosylated serum protein in the higher dose group was significantly lower than baseline after 7 days of treatment (2.19 ± 0.27 vs 2.44 ± 0.28 mmol·L-1, P = 0.000) , but there was no significant difference in the standard dose group. There was no significant difference in the rate of reaching FBG targets of ≤ 5.7, ≤ 6.1 and ≤ 7.0 mmol·L-1 between the two groups within 7 days of treatment, as well as the incidence of hypoglycemia. Conclusion Compared with the standard initial dose, basal insulin therapy at a higher initial dose (0.4 U·kg-1) in newly diagnosed adult overweight and obese T2DM patients, resulted in faster compliance of FBG with no increased risk of hypoglycemia.