OBJECTIVE： To establish the method for simultaneous determination of paeoniflorin， amygdalin， ferulic acid and ligustrazine in Modified buying huanwu decoction. METHODS： RP-HPLC method was adopted. The determination was performed on YMC C18 column with the mobile phase consisted of acetonitrile-0.1％ phosphoric acid （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelengths were set at 320 nm （ferulic acid）， 230 nm （paeoniflorin）， 207 nm （amygdalin）， 280 nm （ligustrazine）. The column temperature was 30 ℃， and sample size was 10 μL. RESULTS： The linear ranges of paeoniflorin， amygdalin， ferulic acid and ligustrazine were 0.191 2-1.912 μg/mL （r＝0.999 6），0.117 4-1.174 μg/mL （r＝0.999 6），0.011 5-0.115 μg/mL （r＝0.999 8） and 0.001 66-0.016 6 μg/mL（r＝0.999 7）， respectively. The limits of quantitation were 1.912， 1.174， 0.115， 0.016 6 μg/mL， and the limits of detection were 0.25， 0.40， 0.05， 0.008 5 μg/mL， respectively. RSDs of precision， stability and reproducible tests were all lower than 2.0％. The recoveries were 96.9％-100.3％（RSD＝1.3％，n＝6），95.1％-100.3％（RSD＝2.2％，n＝6），95.3％-100.2％（RSD＝2.0％，n＝6）and 97.0％-100.0％（RSD＝1.3％， n＝6）. CONCLUSIONS： The method is reliable， simple and accurate， and is suitable for simultaneous determination of paeoniflorin， amygdalin， ferulic acid and ligustrazine in Modified buyang huanwu decoction.