OBJECTIVE: To establish the determining method of puerarin in plasma with high performance liquid chromatography. METHOD: The 0.58 mol·L^-1perchloric acid was used to precipitate the protein. Shimpack CLC-ODS column(5μ, 150 mm X 4.6 mm) was used as analytical column. YWG-C₁₈H₃₇ was used as pre-column. The mobile phase consisted of methanol-5 .625 mol · L^-1acetic acid-water(25:3:72).The rate of mobile phase was 1 .00 ml. RESULTS: The recovery of this method was 91，0%，and the repeatability was RSD=0.93(n=6).CONCLUSION : The method could be used to determine puerarin in vivo.