OBJECTIVES: To assess the health effectiveness, cost and cost-effectiveness of different Viral Load Test (VLT) in Response Guided Treatment of peg-interferon alpha-2a plus ribavirin for chronic hepatitis C.  METHODS: Decision tree of COBAS test and domestic test were developed on the basis of Response Guided Treatment (RGT), and short term test efficacy, treatment response and long term outcomes of SVR or Non SVR were derived from literatures. RESULTS: The long term result of COBAS test plus standard treatment was 30.57LYs and 19.11QALYs, while the total cost was 70,287.91CNY. 30.34Lys and 18.89QALYs were acquired by domestic test while the total cost was 74,151.83CNY. Relatively, 0.23 QALYs (0.23LYs) were prolonged and 3,864CNY was saved per CHC patient via COBAS test compared with domestic one, which also denoted COBAS test to be a less costly and more effective / dominant measure. In addition, sensitivity analysis showed the result was not sensitive to main indicators, including test price, week-4 and week-12 treatment response rate, week-4 and week-12 false negative rate of domestic test, SVR rate of 24-week treatment for cEVR, and proportion of non-EVR in RNA positive in 12^th week.  CONCLUSIONS: Compared with domestic HCV RNA test, for the short term treatment course, COBAS test can identify RVR & EVR more accurately, make more appropriate decisions of course period and have more patients achieve SVR. And in long term perspective, COBAS test plus appropriate course of treatment can prolong patient’s life year, improve patient’s life quality as well as decrease total medical expense due to less disease progress.