Hepatitis C, caused by infection of hepatitis C virus (HCV), is an acute or chronic infectious disease involved with a significant proportion of population worldwide. In general, 50%-85% of the infections might become chronic hepatitis C or carriers, thereafter developing into cirrhosis and hepatocellular carcinoma. Currently, the standard of care for chronic hepatitis C is pegylated interferon α (PEG-INFα) plus ribavirin (RBV). Nevertheless, about 50% of the patients infected with HCV genotype 1 fail to achieve sustained virological response (SVR) although they share the same or similar diagnosis. A number of clinical studies show that the efficacy of standard of care depent on both virus and host factors. The predictors of SVR on the HCV side include viral load and genotype; on the host side, gender, age, alcohol consumption, fibrosis stage, co-infection with other virus, genetic polymorphisms are included. Among those, the most important elements that may play significant roles in the individualized treatment of HCV infections are the viral load and genotype as well as the variation in the host gene interleukin 28B (IL-28B).