AIM: To study the efficacy and safety of Fuzhenghuayu capsule (FZHY capsule, a capsule for strengthening body resistance to remove blood stasis) against liver fibrosis due to chronic hepatitis B. METHODS: Multicenter, randomized, double blinded and parallel control experiment was conducted in patients (aged from 18 to 65 years) with liver fibrosis due to chronic hepatitis B. Hepatic histologic changes and HBV markers were examined at wk 0 and 24 during treatment. Serologic parameters (HA, LM, P-Ⅲ-P, Ⅳ-C) were determined and B ultrasound examination of the spleen and liver was performed at wk 0, 12 and 24. Liver function (liver function and serologic parameters for liver fibrosis) was observedat wk 0, 6, 12, 18 and 24. Blood and urine routine test, renal function and ECG were examined before and after treatment. RESULTS: There was no significant difference between experimental group (110 cases) and control group (106 cases) in demographic features, vital signs, course of illness, history for drug anaphylaxis and previous therapy, liver function, serologic parameters for liver fibrosis, liver histologic examination (99 cases in experimental group, 96 cases in control group), HBV markers, and renal function. According to the criteria for liver fibrosis staging, meanscore of fibrotic stage(s) in experimental group after treatment (1.80) decreased significantly compared to the previous treatment (2.33, P＜0.05), but there was no significant difference in mean score of fibrotic stage(s) (2.11 and 2.14 respectively). There was a significant difference in reverse rate between experimental group (52%) and control group (23.3%) in liver biopsy. With marked effect on decreasing the mean value of inflammatory activity and score of inflammation (P＜0.05), Fuzhenghuayu capsule had rather good effects on inhibiting inflammatory activity and was superior to that of Heluoshugan capsule. Compared to that of pretreatment, there was a significant decrease in HA, LM, P-Ⅲ-P and Ⅳ-C content in experimental group after 12 and 24 wk of treatment. The difference in HA, LM, P-Ⅲ-P and Ⅳ-C content between 12 and 24 wk of treatment and pretreatment in experimental group was significantly greater than that in control group (P＜0.01-0.05). The effect, defined as two of four parameters lowering more than 30% of the baseline, was 72.7% in experimental group and 27.4% in control group (P＜0.01). Obvious improvement in serum Alb, ALT, AST and GGT was seen in two groups. Compared to that of control group, marked improvement in GGT and Alb was seen in experimental group (P＜0.05). The effective rate of improvement in serum ALT was 72.7% in experimental group and 59.4% in control group. No significant difference was seen in blood and urine routine and ECG before and after treatment. There was also no significant difference in stable rate in ALT and serologic parameters for liver fibrosis between experimental group and control group after 12 wk of withdrawal. CONCLUSION: Fuzhenghuayu capsule has good therapeutic effects on alleviating liver fibrosis due to chronic hepatitis B without any adverse effect and is superior to that of Heluoshugan capsule.