OBJECTIVE To evaluate the long-term cost-effectiveness of once-daily biphasic insulin aspart (BIAsp 30) versus insulin glargine (IGlarg) in patients with type 2 diabetes (T2DM) in China. METHODS The validated and peer-reviewed CORE Diabetes Model was employed to simulate disease progression and determine the total direct medical cost, life years (LYs) and quality-adjusted life years (QALYs) over 30 years. Simulated cohorts and treatment effects were based on the Chinese subgroup (n=422) in the Easymix study (identifier in ClinicalTrials.gov: NCT01123980) which was an open-label, randomized, two-arm and multicenter trial among insulin-na��ve people with T2DM. Treatment costs were based on insulin doses in the trial and market retail prices in China. Management and complication costs were obtained from Chinese published data in 2011 and adjusted to the price level of 2013 with consumer price index. An annual discounting rate of 3% was used for both costs and health outcomes. One-way sensitivity analyses and probability sensitivity analyses were performed. RESULTS Treatment with BIAsp 30 is associated with LY gain of 0.11 (13.72 vs 13.60) and QALY gain of 0.10(9.66 vs 9.56) compared with IGlarg over 30 years. In terms of total average cost per patient, BIAsp 30 was less costly than IGlarg (CNY-46 809, CNY 197 496 vs 244 305). Sensitivity analyses demonstrated robustness of the results. CONCLUSION Compared with once daily IGlarg, treatment with BIAsp 30 is projected to be associated with improved life expectancy and reduces direct medical cost, represents a dominant treatment option among patients with T2DM.