Abstract: The study aims to evaluate the effect of long-term pretreatment of the rat with Wuzhi tablet (WZ) on hepatic and intestinal CYP3A mRNA and protein expression and activity. Male Sprague-Dawley rats were orally administered of midazolam (2 mg·kg^-1) with or without 14 days of pretreatment of WZ (0.25 g·kg^-1) to determine CYP3A activity. Meanwhile, RNA and protein of rats liver and intestine samples were prepared 24 h after the last dose of 14 days of WZ treatment to determine CYP3A mRNA and protein expression. Long-term treatment of WZ increased the mRNA expression of hepatic Cyp3a1, Cyp3a9 and intestinal Cyp3a9 by 54.6%, 188.3% (P<0.05) and 48.2% (P<0.05), respectively;and increased the protein expression of hepatic CYP3A by 43.2%. However, after long-term treatment of WZ, the AUC of orally administered of midazolam in the WZ group was increased 29.9% (WZ pretreatment group) and 154.2% (WZ coadministered group) compared to that of control group. In conclusion, long-term treatment of WZ increased the mRNA and protein expression of CYP3A, while could inhibit the activity of CYP3A.