Objective: To establish an HPLC method for the simultaneous determination of oleanolic acid and ursolic acid in Uygur medicine Ziziphora clinopodioides. Method: A ODS C18(4.6 mm×150 mm

10 μm) column was adopted. The mobile phase consisted of methanol and 0.03 mol ·L-1 phosphate buffer (pH 3

90:10). Detection wavelength was at 214 nm. The flowrate was 0.5 mL ·min-1. The injection volumn was 10 μL. Result: oleanolic acid was linear in the range was 0.4-1.2 g ·L-1 (r=0.999 6).ursolic acid was linear in the range was 0.6-1.8 g ·L-1 (r=0.999 6)

and the linear relationship is accurate. The average recovery (n=6) of oleanolic acid was 99.5% (RSD 1.19%) and ursolic acid was 102.3%(RSD 1.25%). Conclusion: The method was simple

feasible and reproducible

and can be used for the simultaneous determination of oleanolic acid and ursolic acid in Z. clinopodioides.