OBJECTIVE： To establish a method for determining the plasma concentration of paeoniflorin and phillyrin and pharmacokinetic study before and after intragastric administration of Qianliean granules. METHODS： LC-MS/MS method was adopted. The column was Waters C18 with mobile phase consisted of acetonitrile （A）-2 mmol/L ammonium acetate （containing 0.05％ formic acid）（B） （0-9 min：15％ A→50％ A；9-11 min：50％ A→90％ A；11-17 min：90％ A；17-19 min：90％ A→15％ A；19-20 min：15％ A）， at the flow rate of 0.6 ml/min； column temperature was 35 ℃ and the volume was 20 μl； quantitative ions were paeoniflorin m/z 525.2 → m/z 449.0， phillyrin m/z 552.3 → m/z 355.3. 7 SD male rats were docked to collect blood 0.5 ml from angular vein 0.25， 0.5， 0.75， 1， 1.5， 2， 3， 4， 6， 8， 10， 12， 24 h after administration Qianliean granule solution 1 g （medicinal materials）/kg to determine the blood concentration of drugs. DAS 2.1.1 software was employed to calculate pharmacokinetic parameters. RESULTS： The linear range of paeoniflorin and phillyri were 5.0-2 500.0 μg/L （r＝0.997 9） and 2.0-2 000.0 μg/L （r＝0.998 2）， respectively； RSD of precision test was less than 5.5％ （n＝5）； the method recovery were 96.0％-104.0％ and 92.0％-107.0％， the extration recovery were 71.4％-83.5％ and 81.5％-92.3％ and RSD of stability test was less than 5.0％ （n＝3）. The pharmacokinetic parameters of paeoniflorin and phillyrin were as follows as t1/2 of （2.206±0.631） and （1.355±0.317） h； cmax of （1 504.069±620.885） and （79.043±15.568） μg/L； tmax of （1.000±0.250） and （1.214±0.267） h； AUC0-24 h of （4 897.645±2 207.577） and （263.475±54.795） μg·h/L； CL of （5.025±2.773） and （76.253±13.986） L/（h·kg）. CONCLUSIONS： The method is highly sensitive， exclusive， simple， accurate and reliable， and can be applied to study the pharmacokinetic characteristics of paeoniflorin and phillyrin in rats in vivo.