Objective: To investigate the effects and mechanisms of Yinzhihuang on transcription of CYP3A4. Methods: The Chang Liver cells were cultured with 0.01μM, 0.1μM, 1μM Yinzhihuang respectively for 24h, 36h and 48h. The expression of CYP3A4 mRNA was detected by RT-PCR and dual-luciferase reporter assay. Results: The Chang Liver cells were cultured with Yinzhihuang of different concentration for 24h and 36h could obviously increase the expression of CYP3A4 mRNA (P<0.05). The Chang Liver cells that transfected CAR vector were cultured with different concentrations of Yinzhihuang for 36h could activate transcription of CYP3A4. Conclusions: Yinzhihuang may increase the transcriptional expression of CYP3A4 in Chang Liver cells mediated by CAR.