[Objectives] To screen the identification conditions of citric acid in Wuhuang Oral Liquid by thin layer chromatography,and establish the quality control method for citric acid in Wuhuang Oral Liquid.[Methods] Different treatment methods were adopted for test sample,developing agent,and drying time,thin layer chromatography separation condition and spot definition were taken as indicators to conduct experiment,to select optimal thin layer identification method. [Results] Methanol was used as the extraction solvent,ultrasonic treatment,ether extraction,dissolution by anhydrous ethanol as treatment conditions of test sample; upper solution of butyl acetate-formic acid-water(4 ∶ 2 ∶ 2) after placing one hour was taken as developing agent; 0. 1% bromocresol green(BCG) as the developer; when developing the color in 3 hours after development,in thin layer chromatograph,there appeared the same strip in the same position of test sample of Wuhuang ORAL Liquid and control substance,no obvious trailing phenomenon,and the color was uniform and clear.[Conclusions]The thin layer chromatography identification conditions can be used as the method for quality control of Wuhuang Oral Liquid. [Objectives] To screen the identification conditions of citric acid in Wuhuang Oral Liquid by thin layer chromatography, and establish the quality control method for citric acid in Wuhuang Oral Liquid. [Methods] Different treatment methods were applied for test sample, developing agent, and drying time, thin layer chromatography separated condition and spot definition were taken as indicators to conduct experiment, to select optimal thin layer identification method. [Results] Methanol was used as the extraction solvent, ultrasonic treatment, ether extraction, dissolution by anhydrous ethanol as treatment conditions of test sample; upper solution of butyl acetate-formic acid-water (4: 2: 2) after placing one hour was taken as developing agent; 0.1% bromocresol green (BCG) as the developer; when developing the color in 3 hours after development, in thin layer chromatograph, there have been the same strip in the same position of test sample of Wuhuang ORAL Liquid and control substance, no obviou s trailing phenomenon, and the color was uniform and clear. [Conclusions] The thin layer chromatography identification conditions can be used as the method for quality control of Wuhuang Oral Liquid.