Hepatitis C virus (HCV) infection frequently causes chronic hepatitis, which is linked to the development of liver cirrhosis and hepatocellular carcinoma. Most physicians who practice Kampo medicine in Japan have observed that Kampo medicine can be as effective as interferon therapy in the treatment of chronic hepatitis C. In the present study, to evaluate the effect of Kampo medicine on chronic hepatitis C, clinical treatment was assessed in short-term and long-term study, and it was shown that ninjin-yoei-to (Formula ginseng compositae: TJ-108) was very effective. Therefore, to find the most active herbal component of TJ-108 in the treatment of HCV, Citrus Unshiu Peel, Schisandra Fruit, and Polygala Root, which are specific to TJ-108, were screened using an in vitro HCV infection model. Among the three herbs, Schisandra Fruit was found to be most active. In the next step, Gomisin A, an active component of Schisandra Fruit, was studied using an in vitro model with MOLT-4 cells and an animal model of immunologically induced acute hepatic failures. It is concluded that the therapeutic effect of TJ-108 on chronic hepatitis C is from the inhibitory effect on HCV infection, and also from the protective effect on immunological hepatopathy of Schisandra Fruit and its lignan component, Gomisin A.