Objective: To study the pharmacokinetics of benzoic acid and cinnamic acid in rats plasma after oral administration of Benzoinum liquid or the mixing liquid of Benzoinum and Borneolum Syntheticum. Method: SD rats were divided into two groups randomly

giving Benzoinum liquid or the mixing liquid of Benzoinum and Borneolum Syntheticum respectively

collecting the plasma samples at different time. Then determining benzoic acid and cinnamic acid contents

and calculating the pharmacokinetic parameters. Result: The experiments showed the Tmax were (41.57±1.99)

(11.42±3.78)min for benzoic acid

(32.86±3.13)

(11.71±2.96)min for cinnamic acid. The maximum plasma concentration(Cmax) were(34.93±11.65)

(40.35±22.72) mg·L-1 for benzoic acid

(2.96±1.10)

(3.43±1.38)mg·L-1 for cinnamic acid. The AUC(0~∞) were (4 481.42±879.21)

(3 942.21±977.52)min·μg-1·mL-1 for benzoic acid (601.16±45.84)

(401.33±23.35)min·μg-1·mL-1 for cinnamic acid. Conclusion: In the compatibility of Benzoinum with Borneolum Syntheticum the Tmax of benzoic acid and cinnamic acid were significantly reduced

suggesting that the compatibility of the two drugs can accelerate the absorption speed of benzoic and cinnamic acid in rats.