OBJECTIVE： To establish a method for the simultaneous determination of imperatorin and isoimperatorin in Qingxuan tablet. METHODS： UPLC was performed on the column of ACQUITY UPLC BEH C18 with mobile phase of methanol-water （gradient elution） at a flow rate of 0.3 ml/min， the detection wavelength was 248 nm， column temperature was 30 ℃， and the injection volume was 3 μl. RESULTS： The linear range was 1.305-13.05 μg/ml for imperatorin （r＝0.999 9） and 1.096-10.96 μg/ml for isoimperatorin（r＝0.999 9）； RSDs of precision， stability and reproducibility tests were lower than 1％； recoveries were 97.45％-100.10％ （RSD＝1.00％，n＝9） and 98.33％-101.20％ （RSD＝1.01％，n＝9）， respectively. CONCLUSIONS： The method is accurate， fast and reliable， and can be used for the simultaneous determination of imperatorin and isoimperatorin in Qingxuan tablet.