To establish high-performance liquid chromatography method using cyclodextrin as a mobile phase additive for the determination of ursolic acid and oleanolic acid in Corni Fructus, providing a basis for quality control of Corni Fructus.

Molecular design and response surface method were used to optimize the determination method of ursolic acid and oleanolic acid in Corni Fructus. Agilent Eclipse XDB C₁₈ column (150 mm×4.6 mm, 5 μm) was adopted as the stationary phase, the mobile phase was 3 mmol·L^-1 γ-cyclodextrin solution (contained 0.05% phosphoric acid)-acetonitrile (60∶40), the flow rate was 1.0 mL·min^-1, the column temperature was 25 ℃ and the detecting wavelength was 210 nm.

The resolution of chromatographic peaks of ursolic acid and oleanolic acid was 3.81. Linearities were good in the range of 400-4 000 ng for ursolic acid and in the range of 200-2 000 ng for oleanolic acid. The RSDs for precision, reproducibility, and stability were less than 1.4%, 1.8%, and 1.7%, respectively. The recovery rates were 98.5% (RSD=1.7%) and 99.1% (RSD=2.0%). The contents of ursolic acid in three batches of Corni Fructus were 2.66 mg·g^-1, 2.35 mg·g^-1 and 2.91 mg·g^-1, and those of oleanolic acid were 0.83 mg·g^-1, 0.78 mg·g^-1and 1.12 mg·g^-1, respectively.

This method is simple, accurate, reliable, and environmental friendly, and can be used as a quality control for Corni Fructus.