Abstract: To establish a method for the determination of caffeic acid and chlorogenic acid Vernonia patula by HPLC. The separation was performed on Welch Ultimate XB-C18（4.6 mm×250 mm,5 μm）with the acetonitrile-0.2% phosphoric acid aqueous solution as the mobile phase with gradient elution. The volume flow rate was 1.0 mL/min. The detection wavelength was 327 nm. The column temperature was 25 ℃. The linear range of caffeic acid and chlorogenic acid were 47.84~239.2 μg/mL（R=0.999 8）、10.05~50.25 μg/mL（R=0.999 9）, and the average recoveries （n=6） were 96.69%（RSD=0.74%）、102.10%（RSD=2.00%）. This paper established a method for the contents of chlorogenic acid and caffeic acid in Vernonia patula. The method is accurate, sensitive, credible and repeatable. It can be applied to the quality control of Vernonia patula.

Key words: Vernonia patula, chlorogenic acid, caffeic acid, HPLC