Abstract: Objective To determine 3 components in decoction of Rheum and Moutan by HPLC simultaneously. Methods The seperation of 3 ingerdients was achieved on a Kromasil C₁₈ column(250 mm×4.6 mm,5 m) with gradi-ent elution using solvents of acetonitrile 0.1% phosphoric acid solution. The speed of flowing phase was 1.0 mL·min^-1.The detection wavelength was at 230 nm. Results The linear range was 1.61~16.1 mg·L^-1 for rhein, 1.64~16.4 mg·L^-1 for paeonol and 1.54~15.4 mg·L^-1 for paeoniflorin. Average recoveries of samples were all over 98.0%, RSD were all below 2.0%. Conclusion The method was simple, accurate and can be used as assessment about quality of Decoction of Rheum and Moutan.

Key words: High Performance Liquid Chromatography-Fluorescence(HPLC), decoction of Rheum and Moutan, main gredients