Abstract: OBJECTIVE A capillary gas chromatographic method for the simultaneous determination of five effective constituents (α-pinene, β-pinene, 1, 8-foliosine, safrole and methyleugenol) in Asiasarum essential oil was developed. METHODS The essential oil was extracted by steam distillation. Pulegone and m-xylene were selected as the double-internal standard substances. The contents of five effective components were analyzed by gas chromatography using an Agilent HP-5 capillary column and a flame ionization detector. The retention time of the peak was applied for qualitative analysis, and the internal standard method was used for quantitative analysis. RESULTS The five components were well separated within 12 min. There were good linear relationships between peak area ratio on the mass concentration and correlation coefficents above 0.997 7. The average recoveries for the added standards and the RSD were 96.7%-99.4% and 1.24%-2.31%, respectively. CONCLUSION This method is simple, fast and accurate for the effective determination of volatile substances of asiasarum.