OBJECTIVES: Hepatitis C virus (HCV) is currently affecting more than 43 million persons in China, but the high cost of the standard drug therapy with pegylated interferon (PEG-IFN) inhibits many HCV infected patients to obtain appropriate treatment. A newly developed domestic low-price PEG-IFN (Peginterferonalfα-2b (40kD, Y shape) is expected to benefit the patients greatly with an equally effective treatment at substantially lower cost. This study provides the first scientific analysis to report the cost-effectiveness of this new drug treatment which is expected to be soon available for HCV infected patients in China. METHODS: Data was obtained from a multicenter, open and randomized, effective drug controlled phase 3 clinical trial. 242 eligible patients were randomized into the treatment group (PEG-IFNα-2b (40kD, Y shape) combined with RBV) and the control group (PEG-IFNα-2a combined with RBV). The effectiveness measure was sustained viral response (SVR). Costs, which were measured by direct medical costs, were obtained from medical records. An incremental cost-effectiveness ratio was calculated and probabilistic sensitivity analysis was conducted based on bootstrapping method. RESULTS: The SVR rate of PEG-IFNα-2b(40kD, Y shape) cohort and PEG-IFNα-2a cohort were 85.44% and 79.52%（p=0.2419）respectively. In the meantime, patients receiving PEG-IFNα-2b(40kD, Y shape) incurred significantly less costs compared to the PEG-IFNα-2a treated control group (CNY 29930.74 vs. 36743.90, P<0.01). CONCLUSIONS: Compared to PEG-IFNα-2a treatment, PEG-IFNα-2b (40kD, Y shape) treatment is equally effective at substantially lower costs. Sensitivity analysis conducted with bootstrapping method indicts a great possibility that PEG-IFNα-2b (40kD, Y shape) treatment is a cost-saving therapy.