Abstract: OBJECTIVE To establish an UPLC-MS/MS method for the determination of lithospermoside and griffonilide in rat plasma and study its pharmacokinetic characteristics. METHODS The separation was performed on Aglient C₁₈ column (100 mm×2.1 mm，1.8 μm) with acetonitrile (A) and 0.1% aqueous formic acid (B) as the gradient elution mobile phase (0~1 min，5%~20%B；1~2 min， 20%~60%B；2~6 min，60%~70%B；6~6.5 min，70%~5%B；6.5~7.5 min，5%B)， the flow rate was 0.3 mL/min， the column temperature was set at 35 ℃ and the injection volume was 3 μL. UPLC-MS/MS was used to detected the concentration of lithospermoside and griffonilide in rat plasma after oral administration of Semiaquilegiae Radix. The pharmacokinetics parameters of lithospermoside and griffonilide were calculated by DAS 2.0 software. RESULTS Good linearity was found in lithospermoside and griffonilide within linear range from 0.701 9 ~ 140.4 ng/mL and 1.120 2 ~ 240.4 ng/mL， respectively. The RSD of accuracy and intra-/inter-day precision were less than 15%. The recovery of the method was ranged from 87.22% to 107.75%. Lithospermoside and griffonilide were absorbed rapidly， the highest plasma concentration reached at 0.5 h， and the drug removed from body very fast and eliminated completely in 24 h. CONCLUSION This method is accuracy and stability for the study on pharmacokinetics of lithospermoside and griffonilide in rat plasma.