Objective To explore the mechanism of Fufangbiejiaruanganpian(FFBJRGP) treating liver fibrosis. Methods Needle biopsies before and after treatment with FFBJRGP were done in 65 patients with chronic viral hepatitis B, and the liver tissues were studied with Ishak scoring system to evaluate the effects of treatment. The activation, proliferation and apoptosis of hepatic stellate cells (HSCs) in the liver specimens were determined by using the double immunohistochemical staining of in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labelling method (TUNEL) and smooth muscle actin (SMA). Results Compared with the specimens before treatment, the stages of liver fibrosis and histological activity grades in liver tissues were significantly improved after treatment with FFBJRGP for 6 months (mean value: P<0.01 respectively). Furthermore, the number of activated HSCs was decreased remarkably after therapy with FFBJRGP, while the apoptosis of activated HSCs was significantly increased (both P<0.01, vs before treatment, respectively). Conclusion Inhibition of activation of HSC and promotion of apoptosis of the activated HSCs might constitute the mechanism of therapeutic effect of FFBJRGP in the prevention of fibrosis of the liver.