Objective: To establish a method for determination of β-caryophyllene in essential oil from Clausenae folium produced in Hainan by GC. Method: The essential oil was extracted by steam distillation and the determination was carried out on an SE-54 capillary column (0.25 mm×30 m

0 25 μm). The temperature program was as follows:the initial temperature was set at 143℃

and hold for 17 min

and then programmed to 250℃ at 20℃·min-1. The detector was FID

and its temperature was set at 280℃. The carrying gas was nitrogen and its flow rate was 1.2 mL·min-1. Result: The linear range of β-caryophyllene was 0.081 0-0.810 g·L-1 (r=0.999 7). The average recovery of β-caryophyllene was 98.93% (n=6

RSD 2.54%). Conclusion: The developed method is simple

quick and accurate

which provided basis for the quality control of Clausenae folium.