Objective:To observe the inhibitive effect of the serum containing Abrus mollis on hepatitis B virus(HBV). Method: HepG2.2.15 cells were cultured in medium containing the serum with A. mollis for 72 h and 144 h. The Effect of the serum containing A. mollis on HBsAg and HBV DNA reproduction in culture media of the HepG2.2.15 cells were determined by ELISA and fluorescence quantitative pdymerase chain reaction(FQ-PCR). Result: The serum containing A. mollis had a inhibiting effect on the HBsAg and HBV DNA reproduction with maximum inhibition ratio adding up to 34.4% and 41.7% respectively in which the affective time is 144 h and the density is 30 g·kg-1·d-1. Conclusion: A. mollis can significantly inhibit HBV in vitro.