Abstract: OBJECTIVE To investigate the effect of compound danshen dripping pills on the activity of CYP1A2, NAT2 and XO and to forecast the drug-drug interaction with it, so as to instruct clinician to prescribe rationally.METHODS In thirty volunteers , two-way cross design was used, caffeine was used as a metabolic probe for CYP1A2、NAT2,and XO, before and after compound danshen dripping pills administration, urine samples were collected. The contents of five major metabolites of caffeine in the urine were determined by RP-HPLC method. And then the activity change of CYP1A2，NAT2 and XO was evaluated by the ratio of metabolites of caffeine .RESULTS It was found that the average activity of CYP1A2,NAT2 and XO were 4.20±1.54，0.36±0.12，0.33±0.05 before treatment ,and 14 days after administration, the average activity of CYP1A2,NAT2 and XO were 4.26±1.95，0.32±0.12，0.32±0.07， and 28 days after administration, the average activity of CYP1A2,NAT2 and XO were 4.35±1.26，0.30±0.11，0.31±0.04. There was no statistical significance between before treatment and after taking medicine 14 days for CYP1A2,NAT2 and XO and also there was no statistical significance between before treatment and after taking medicine 28 days for CYP1A2 and NAT2. But there was statistical significance between before treatment and after taking medicine 28 days for XO. CONCLUSION Compound danshen dripping pills have no influence on CYP1A2 and NAT2,so compound danshen dripping pills do not modify the efficacy of drugs which metabolized by CYP1A2 and NAT2 taken simultaneously. But compound danshen dripping pills may modify the efficacy of drugs which metabolized by XO taken simultaneously.