OBJECTIVES: Sunitinib is a multitargeted receptor tyrosine kinase inhibitor that has demonstrated its efficacy in treating Gastrointestinal stromal tumor (GIST) patients who are no longer responded to imatinib 400mg/day. The purpose of this study is to evaluate the cost-effectiveness of sunitinib as a second-line treatment in patients with advanced GISTs in China from a third party payer’s perspective. METHODS: A Markov model was developed to simulate disease progression and to determine cost and effectiveness outcomes over a 5-year time horizon. The different second-line treatment arms compared were sunitinib 50 mg/day (4 weeks on and 2 weeks off), imatinib 600 mg/day, imatinib 800 mg/day, and best supportive care (BSC). The probabilities of state transitions and utilities were obtained from previous published trials. Resource use and costs data were obtained from previous studies and public sources. A 3.5% annual discount rate after the first year was applied to both costs and outcomes. The incremental cost-effectiveness ratios (ICER) between treatment with sunitinib vs. other treatment options were calculated. RESULTS: In the base case, treatment with sunitinib vs. imatinib 600 mg resulted in 0.744 PFLY gained, 0.423 LY gained and 0.398 QALYs gained at an incremental cost of RMB14,750. The ICER was RMB37,023 per QALY gained. Treatment with sunitinib was dominant compared with imatinib 800 mg, with lower costs and higher QALYs .  Treatment with sunitinib vs BSC resulted in patients’ benefits of 0.257 PFLY gained, 1.357 LY gained and 0.836 QALYs gained at an incremental cost of RMB106,889. The ICER was RMB127,801 per QALY gained. CONCLUSIONS: Among patients with advanced GISTs who have failed imatinib 400mg/day as the first-line treatment, sunitinib provides greater clinical benefit than high-dose imatinib or BSC. In the Chinese setting, sunitinib is estimated to be either cost-saving or cost-effective compared with imatinib 800 mg, imatinib 600mg or BSC.