OBJECTIVE：To evaluate the economic value of dapagliflozin combined with metformin in the treatment of type 2 diabetes mellitus （T2DM）. METHODS ：Based on related literatures and phase 3 randomized controlled clinical trial （RCT）of metformin alone or combined with dapagliflozin for T2DM，Markov model was built to simulate the dynamic changes of 3 schemes such as 5 mg dapagliflozin combined with metformin ，10 mg dapagliflozin combined with metformin or metformin alone （the dose of metformin were all 1 500 mg）in the treatment of T 2DM patients without or with complications and death . Quality adjusted life years（QALYs）was used as a health output indicator and the threshold of willingness-to-pay was 3 times of GDP in 2019. Cohort simulation in Markov model was applied to obtain long-term effect and cost of 3 schemes in the treatment of T 2DM. The incremental cost-effectiveness ratio （ICER）was analyzed ；the sensitivity of cost ，utility and discount was analyzed to check the stability of the analysis result. RESULTS ：According to the results of Markov model cohort simulation ，after 10 years of disease progression，compared with metformin alone ，ICER of 5 mg dapagliflozin combined with metformin was 41 259.17 yuan/QALYs， and that of 10 mg dapagliflozin combined with metformin was 92 824.85 yuan/QALYs. Compared with 5 mg dapagliflozin combined with metformin ，ICER of 10 mg dapagliflozin combined with metformin was 1 209 525.95 yuan/QALYs. Extension of termination time to 20 or 30 years had no effect on results. According to the sensitivity analysis ，the change of key parameters in the set range did not affect the model results ，indicating the result was stable. CONCLUSIONS ：For T 2DM，5 mg dapagliflozin combined with metformin is more cost-effective .