Abstract: OBJECTIVE To study the effects of cultivated growing and wild growing Polygala tenuifolia Willd specieses and different extracted methods on volatile oil of Polygala tenuifolia Willd, characteristics of fingerprints was set up based on supercritical CO₂ extraction method. METHODS The volatile oil of Polygala tenuifolia Willd of different origins was refined through the supercritical CO₂ extraction, and was analyzed by GC fingerprint. RESULTS The extraction rate of volatile oil from Polygala tenuifolia Willd through the supercritical CO₂ extraction was between 0.29%-0.82%, and the components of volatile oil were basically the same compared with those extrated by steam distillation; the type of the volatile oil in cultivation was more abundant compared with the components of volatile oil in wild Polygala tenuifolia Willd. CONCLUSION The method of the supercritical CO₂ extraction is high efficiency, which provides a better extraction method for the volatile oil of Polygala tenuifolia Willd.