Objective: To establish the method for analyzing isofraxidin in rat blood serum and investigate pharmacokinetic indexes of isofraxidin after oral administration of Yinxieling or Sarcandra glabra(Thumb.) Nakai. Method: Sprague-Dawley rats were administrated Yinxieling or decoction of S.glabra respectively. Serum concentration of isofarxidin was measured by HPLC. The results were analyzed by pharmacokinetic software DAS(2.0). Result: The linearity of the calibration curve was good in the range of 0.25-12 mg ·L-1 for isofraxidin and the detection limit for isofraxidin were 0.25 mg ·L-1.The extraction recoveries of isofraxidin were 70.9%-71.9% with RSD was 1.1%. The intra-day precision and inter-day precision of isofraxidin were lower than 8.9%. The difference of pharmacokinetic parameters between the group of Yinxieling and S.glabra were unremarkable. Conclusion: The method is exclusive

sensitive and accurate. Compound prescription of Chinese medicine did not affect the pharmacokinetics of isofraxidin.