Objective To establish a method for the content determination of the free anthraquinones,garlic acid,berberine hydrochloride and palmatine hydrochloride in Shuangbai San,and to provide a reference for the quality control and chemical analysis of Shuangbai San.Methods HPLC with Eclipse XDB C18 column was used for the determination of the free anthraquinones.The chromatographic conditions were as follows:methanol-0.1 %phosphoric acid as a mobile phase in gradient mode and detection wavelength at 254 nm,flow rate at 1 mL?min-1,and column temperature at 30 ℃.The chromatographic conditions for the determination of gallic acid were as follows:Nucleodur C18 Gravity column,methanol-0.1 %phosphoric acid solution(2 ∶98) as mobone phase,detection wavelength at 273 nm,flow rate at 1 mL?min-1,and column temperature of 40 ℃.The chromatographic conditions for the determination of berbertine hydrochloride and palmatine hydrochloride were as follows.Nucleodur C18 Gravity,acetonitrile-0.1 %phosphoric acid(every 100 mL solution containing sodium dodecyl sulfonate 0.1 g)(39 ∶61) as mobile phase,detection wavelength at 345 nm,flow rate at 1 mL?min-1,and column temperature being 40 ℃.Results The calibration curves were linear(r≥0.999 7),and the average recoveries were all between 95 %～105 %.The total content of free anthraquinones was 5.1172～5.4933 mg?g-1,the content of gallic acid was 1.3376～2.0673 mg?g-1,and that of berbertine hydrochloride and palmatine hydrochloride were 1.2812～1.6855 mg?g-1.Conclusion This method is reliable and simple,which can provide a reference for the quality control and chemical analysis of Shuangbai San.