OBJECTIVE:To establish an HPLC method for the determination of the contents of Ligustrazine in rat's plasma,brain and liver.METHODS:Ligustrazine was separated on Hypersil ODS-C18 column with aspirin as internal standard.The mobile phase consisted of methanol-1.5% glacial acetic acid solution(45∶55,V/V)at a flow rate of 1.0 mL?min-1.The UV detection wavelength was 279 nm.RESULTS:The linear range of ligustrazine in rat's plasma,brain and liver was 0.006 25～7.813 ?g?mL-1,The lowest detectable limits were 0.5 ng?mL-1,1.55 ng?mL-1,and 1.55 ng?mL-1 and the average recoveries were 97.26%,96.44%,and 95.43% respectively with RSD at 3.40%,4.19% and 4.94%,respectively.CONCLUSION:With good linearity,precision and recovery,the method is sensitive and simple,and suitable for pharmacokinetic study and the research of Ligustrazine preparation.