OBJECTIVE： To establish the method for simultaneous determination of gallic acid， rosmarinic acid， liquiritin and ammonium glycyrrhetate in Regan saibisitan granules. METHODS： RP-HPLC method was adopted. The determination was performed on Waters RP-C18 column with mobile phase consisted of acetonitrile-0.2％ phosphoric acid （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelengths were 210 nm （gallic acid， rosmarinic acid and liquiritin）， 230 nm （ammonium glycyrrhetate）. The column temperature was 28 ℃， and sample size was 20 μL. RESULTS： The linear ranges were 0.274 4-7.546 μg for gallic acid （r＝0.999 8）， 0.187 0-5.143 μg for rosmarinic acid （r＝0.999 6）， 0.130 0-3.575 μg for liquiritin （r＝0.999 9） and 0.254 0-6.985 μg for ammonium glycyrrhetate （r＝0.999 8）， respectively. The LOQ were 2.67， 1.36， 1.09 and 2.11 ng， respectively. The LOD were 1.03， 0.62， 0.87 and 0.91 ng， respectively. RSDs of precision， stability and repeatability tests were all less than 2.0％. The average recoveries were 97.26％-101.00％ （RSD＝1.1％，n＝9），97.66％-101.80％（RSD＝1.3％，n＝9）， 97.45％-101.70％ （RSD＝1.4％，n＝9），97.74％-101.70％（RSD＝1.4％，n＝9）. CONCLUSIONS： The method is simple， accurate and reproducible， and can be applied for simultaneous determination of gallic acid， rosmarinic acid， liquiritin and ammonium glycyrrhetate in Regan saibisitan granules.