Abstract: OBJECTIVE To investigate pharmacokinetics of ginkgo flavones in Beagle dogs by quercetin, a typical aglycone of ginkgo flavones. METHODS Blood samples were collected at scheduled time points after a single oral administration of ginkgo leaf tablets. The concentration of quercetin in plasma was determined by HPLC-ECD after solid-phase extraction (SPE) and hydrolyzed by HCl. The main parameters of pharmacokinetics were calculated by DAS software. RESULTS The concentration-time course of quercetin was best fitted to a two-compartment model after oral administration. The main pharmacokinetic parameters were t_1/2z 5.67 h, AUC_0-t 63.8 mg·L^-1·h, C_max 15.9 mg·L^-1. CONCLUSION The method is simple, sensitive and accurate. It provides an important method for the determination and pharmacokinetics study of quercetin.