OB JECTIVE To evaluate the cost-effectiveness of durvalumab for consolidation therapy after chemoradiotherapy for unresectable stage Ⅲ non-small cell lung cancer from the perspective of the Chinese health care system. METHODS A Markov model was developed by using updated four-year survival data from the PACIFIC trial in May 2021 and relevant literature. The cost-effectiveness of durvalumab for consolidation therapy after chemoradiotherapy for unresectable stage Ⅲ non-small cell lung cancer was evaluated by using quality-adjusted life years （QALYs）as health output index with 20-year simulation time frame and a 2-week cycling period. The costs and health output were discounted using discount rate of 5％；one-way sensitivity analysis and probabilistic sensitivity analysis were used to examine the robustness of the model simulation results. RESULTS The results of the base analysis showed that compared with placebo group ，durvalumab resulted in 0.73 QALYs at an incremental cost of 1 076 062.86 yuan and an incremental cost-utility ratio （ICER）of 1 467 546.54 yuan/QALY，which was much higher than 3-fold per capita gross domestic products （GDP）in 2020（217 713 yuan）as willingness-to-pay （WTP）threshold. The results of one-way sensitivity analysis showed that the price of durvalumab and discount rate had a great impact on ICER. Probabilistic sensitivity analysis showed no cost-effective advantage for durvalumab when the WTP threshold was three times of GDP per capita in 2020 （217 713 yuan）. CONCLUSIONS From the perspective of Chinese health care system ，there is no cost-effective advantage to the use of durvalumab for consolidation therapy after chemoradiotherapy for unresectable stage Ⅲ non-small cell lung cancer when the WTP threshold was three times of GDP per capita in 2020.