Abstract: OBJECTIVE To develop an HPLC method for the determination of imatinib and its metabolites CGP74588, and study the induction effects of Fufang Kushen injection on pharmacokinetics of imatinib and CGP74588 in rats. METHODS Twenty-four SD rats were randomly designated as vehicle control, low-dose, medium-dose and high-dose0.1, 0.2, 0.4 mL·(100 g)^-1, i.p. Fufang Kushen injection treatment groups. The treatment were given once a day for 9 consecutive days. On the experimental day (day 10), rats were treated with the imatinib (30 mg·kg^-1) orally. RESULTS Low-dose Fufang Kushen injection does not influence the pharmacokinetics of imatinib and GCP74588. However, the effects of the medium-and high-dose Fufang Kushen injection on imatinib were significant. In medium-dose group, the C_max and AUC_(0-∞) of imatinib reduced 39.68% and 35.70%, while the CLz/F increased 62.96%, but it had no obvious effect on its metabolites CGP74588. In high-dose group, imatinib C_max and AUC_(0-t) were decreased by 49.04% and 33.23%, while Vz/F, CLz/F and MRT_(0-∞) were increased by 1.04 times, 48.15% and 47.31%, respectively. Meanwhile, its metabolites CGP74588 C_max and AUC_(0-∞) reduced 45.15% and 33.95%, with 75.29% and 18.53% increase in CLz/F and MRT_(0-t). CONCLUSION The induction of medium-dose and high-dose Fufang Kushen injection may be related to the induction sites of CYP3A4 and P-gp. In clinical, when imatinib was co-administrated with Fufang Kushen injection, dose adjustment of imatinib should be taken into account.