Objective： To explore the immune mechanism on the water extract of Bushen Jianpi Decoction in inhibiting hepatitis B virus in HepG2 cells transfected with plasmid pHBV1.3-pCR2.1.,Methods,2,After the water extract of Bushen Jianpi Decoction intervened in HepG2 cells transfected with plasmid pHBV1.3-pCR2.1 in two different concentrations（250 μg/ml and 500 μg/ml）， HBsAg and HBeAg contents in cell supernatant were detected by ELISA. After the water extract of Bushen Jianpi Decoction intervened in HepG2 cells transfected with plasmid pHBV1.3-pCR2.1 in concentrations of 500 μg/ml， the expressions of TRL3， p-IRF3 protein were detected by WB， and the expression of ,IFN,-,β, mRNA was detected by qRT-PCR. Bushen Jianpi Decoction intervened in HepG2 cells led that HepG2 cells were transfected with plasmid pHBV1.3-pCR2.1 and TLR3 siRNA down regulated the expression of TLR3. The expressions of TLR3 and p-IRF3 protein were detected by Western blot， and the expression of ,IFN,-,β, mRNA was detected by qRT-PCR.,Results,2,HBsAg of Bushen Jianpi Decoction（500 μg/ml）was significantly decreased compared with that in Bushen Jianpi Decoction（250 μg/ml）and the model group（,P<,0.05，,P<,0.01）. HBeAg of Bushen Jianpi Decoction（500 μg/ml）was significantly decreased compared with that in Bushen Jianpi Decoction（250 μg/ml）and the model group（,P<,0.05，,P<,0.01）. Bushen Jianpi Decoction（500 μg/ml） enhanced TLR3 and p-IRF3 protein expressions， and promoted ,IFN⁃β, mRNA expression in cell（,P<,0.01）. After Bushen Jianpi Decoction intervened in HepG2 cells transfected with plasmid pHBV1.3-pCR2.1， TLR3 siRNA inhibited TLR3 protein expression and p-IRF3 protein expression was decreased significantly and the expression of intracellular ,IFN⁃β ,mRNA expression was decreased significantly.,Conclusion,2,The water extract of Bushen Jianpi Decoction can inhibit hepatitis B virus replication by enhancement of TLR3 effect in HepG2 cells transfected with plasmid pHBV1.3-pCR2.1 and promotion of intracellular IFN-β secretion.