Abstract: The content rate of imperatorin from Clausena lansinm root was used as the study object, the chromatographic conditions such as chromatographic column, mobile phase and detection wavelength were explored, the preparation conditions of the sample solution were optimized by single factor experiment and orthogonal design, the content of imperatorin from Clausena lansinm root was determined. The chromatographic column was Phenomenex Gemini NXC₁₈ （5 μm, 4.6 mm×250 mm）; The mobile phase was methanol-water （55∶45）; The flow rate was 1.0 mL/min and the detection wavelength was set at 300 nm with column temperature of 25 ℃. The extract methods was ultrasonic extraction, the fragmentation degree was acrossing the fourth sieve, extraction solvent was 100% methanol, and extraction time was 30 min. The linear range was 0.065 6~1.640 0 μg（r=0.999 8） and the average recovery was 97.2% with RSD of 0.89%（n=6） for imperatorin. The method can be used to determine the content of imperatorin in Clausena lansinm root.

Key words: Clausena lansinm root, imperatorin, content determination, high performance liquid chromatography