Objective To observe the clinical effects of treatment of Xinjia Dayuan decotion on chronic hepatitis B. Methods 20 patients with CHB were treated with Xinjia Dayuan decotion for 12 weeks. Compared the ALT， HBeAg and HBV-DNA of patients before treatment with 4， 8， 12 weeks of treatment， and analyzed the relationship of them. Results Compared with pre-treatment， the levels of ALT were rised after treatment， significantly at week 8 treatment（P<0.01）， were significantly decreased at week 12 treatment（P<0.01）； The levels of HBeAg and HBV DNA were decreased after treatment， significantly decreased at week 12 treatment（P<0.01）. Conclusion Xinjia Dayuan decotion could reduce the levels of HBeAg and HBV DNA in patients with CHB quickly. According to the difference on the changing track between the ALT， HBV DNA and HBeAg of patients after treatment， we speculated that the antiviral mechanism about Xinjia Dayuan decotion may be done by stimulating the body’s immune response.