Objective: To Detemine human and rat plasma protein binding rate of allicin

and provide a reference for research of allicin into medicinal properties. Method: With ethylparaben as an alternative reference

C18 column was used

mobile phase was methanol-1% formic acid for gradient elution in a flow rate of 1.0 mL · min-1 and detection wavelength was 254 nm. Result: With different concentration of allicin including 75

150

300 mg · L-1

protein binding rates of allicin in rat and human plasma were 23.2%

19.8%

28.1% and 15.5%

25.8%

40.0%

respectively. Conclusion: Allicin has low level in binding to plasma protein of human and rat.HPLC with ethylparaben as alternative reference can be used to determine plasma protein binding rate of allicin.