Abstract: Atractylodes macrocephala Koidz is a traditional medicinal plant, which shows antitumor, anti-inflammatory and antioxidant activities. Volatile oils isolated by steam distillation from A. macrocephala Koidz collected from three diverse localities (Zhejiang, Anhui and Gansu Provinces) were studied by gas chromatography-mass spectrometry (GC-MS). A total of 24 volatile constituents were identified. There were 21 common volatile constituents in three samples. The dominant compound in three samples was atractylone, which occupied 5807% (Zhejiang), 5741% (Anhui), and 5749% (Gansu). Additionally, trifoliumene, berkheyaradulen, 6,10,11,11-tetramethyl-tricyclo［6300(2,3)］undec-1(7)ene, aristolone and isospathulenol which had not been reported in related literatures in A. macrocephala Koidz were also determined.