OBJECTIVE To study pharmacokinetics of ferulic acid and paeoniflorin that are two chief active compounds in Angelic-Paeonia Root Powder (APRP). METHODS After the mice were administered by APRP through ig, HPLC was used to determine ferulic acid and paeoniflorin concentration in serum at different times. 3P87 procedure was used to process concentration-time data. RESULTS Ferulic acid and paeoniflorin were detected from serum in the mice. The pharmacokinetics parameters were: Ferulic acid: Ke = 0.330 +/- 0.085 1/h, Ka = 0.555 +/- 0.133 1/h, t1/2(ka) = 1.249 +/- 0.365 h, t1/2(ke) = 2.101 +/- 0.665 h, Tpeak = 2.606 +/- 0.586 h, Cmax = 6.372 +/- 1.510 mg.L-1, AUC = 41.399 +/- 11.763 mg.h-1.L-1; Paeoniflorin: Ke = 0.511 +/- 0.117 1/h, Ka = 0.656 +/- 0.121 1/h, t1/2(Ka) = 1.056 +/- 0.263 h, t1/2(Ke) = 1.356 +/- 0.281 h, Tpeak = 2.062 +/- 0.396 h, Cmax = 3.401 +/- 0.879 mg.L-1, AUC = 16.047 +/- 3.767 mg.L-1. The present research provided valuable data for rational clinical practice of APRP.