Abstract: Microwave radiation extraction was used for extracting the volatile oil in the Aucklandia lappa decne. The average oil yield obtained from the Aucklandia lappa decne was 4.5%. 52 compounds were identified by gas chromatography mass spectrometry (GC/MS). The compounds account for 93.3% of the total volatile oil. Then the contents of the compounds of the volatile oil were determined using the square peak to normalization. A reliable method with good stability and repeatability was proposed, which can be applied to separate and determine the constituents of volatile oil extracted from Chinese traditional medicines.