[Objective] To analyze volatile oils of Curcuma longa Linn in Hainan Province in different harvest period. [Methods] Taking Curcuma longa Linn in Hainan Province as experimental materials,this paper studied changes in volatile oils of Curcuma longa Linn in different harvest period by gas chromatography / mass spectrometry( GC-MS). [Results] At rhizome expanding stage( October 17),the content of volatile oils of Curcuma longa Linn is the highest,up to 80 m L / kg. Later,the content slightly declines,till the withering period( March 4),the content of volatile oils is 67 m L / kg. In different harvest period,chemical composition of volatile oils of Curcuma longa Linn is basically the same,but the relative content is different. In four harvest times,36,36,34,and 34 kinds of chemical components were identified separately.Main components were Ar-Turmerone,α-Tumerone,Zingiberenol,β-Bisabolene,2-epi-α-Cedrene,Ar-Curcumene,and other sesquiterpene compounds. Ar-Turmerone was the highest in different harvest times,accounting for 49. 259%,33. 794%,33. 610% and 44. 829%,respectively. [Conclusion] In different harvest period,chemical composition of volatile oils of Curcuma longa Linn is basically the same,but the relative content is different. Ar-Turmerone was the highest in different harvest times. [Objective] To analyze volatile oils of Curcuma longa Linn in Hainan Province in different harvest period. [Methods] Taking Curcuma longa Linn in Hainan Province as experimental materials, this paper studying changes in volatile oils of Curcuma longa Linn in different harvest period by gas Results of At rhizome expanding stage (October 17), the content of volatile oils of Curcuma longa Linn is the highest, up to 80 m L / kg. Later, the content slightly declines, Until the withering period (March 4), the content of volatile oils is 67 m L / kg. In different harvest period, chemical composition of volatile oils of Curcuma longa Linn is basically the same, but the relative content is different. 36, 36, 34, and 34 kinds of chemical components were identified separately. Main components were Ar-Turmerone, α-Tumerone, Zingiberenol, β-Bisabolene, 2-epi-α-Cedrene, Ar-Curcumene, and other sesquiterpene compounds. Ar-Turmerone was the highest in di fferent harvest times, accounting for 49. 259%, 33.794%, 33.610% and 44. 829%, respectively. [Conclusion] In different harvest period, chemical composition of volatile oils of Curcuma longa Linn is basically the same, but the relative content is different. Ar-Turmerone was the highest in different harvest times.