Abstract: Objective:To establish a method for determining the contents of six functional components including protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazinein in Chishui sun Vinegar by RP-HPLC. Methods:The separation was performed on the Waters xSelect HSS T3(5 μm,4.6 mm×250 mm)column with gradient elution. The mobile phase was 0.1% phosphoric acid water solution and acetonitrile,and the flow rate was set as 0.8 mL/min. The column temperature was kept at 30 ℃. The detection wavelength was set at 285 nm. Results:The linear ranges of protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazine were within 10.013~320.416,10.015~320.48,10.012~320.384,10.001~320.032,10.021~320.672,10.072~322.304 μg/mL,respectively. The average recovery rates for six components were within 92.93%~104.53% with RSD less than 3%. The limit of determination was 0.30~1.80 μg/mL and the limit of quantification was 1.02~5.52 μg/mL. Except for caffeic acid,the remaining 5 functional components were detected in the seven sun vinegar samples. The amount of vanillic acid in vinegar was much higher than other components. Conclusion:This method is simple,accurate and suitable for the determination of the protocatechuic acid,epicatechin,caffeic acid,vanillic acid,ferulic acid and ligustrazine in Chishui Sun Vinegar.