We aimed to study whether TAP and LMP polymorphisms could influence the severity of liver disease or the response to IFN treatment in patients with chronic HCV infection. TAPZ*0103 gene frequencies in carriers with normal ALT was significantly higher than that in CLD patients. As for the results of IFN responses, LMP7-K gene frequency in sustained-responders was higher than that in non-responders. Multivariate analysis revealed that LMP7-K and HCV RNA quantity were independent factors influencing the outcome of IFN therapy. Furthermore, among patients with a low viral load, the LMP7-K positive patients had a significantly higher ratio of sustained response compared to those without LMP7-K. The TAP2 polymorphism may be closely associated with low hepatitis activity, whereas the LMP7 polymorphism influences the efficacy of IFN treatment and can be a useful predictive parameter in HCV patients with a low viral load.