Abstract: 【Objective】The changes of the components and contents of volatile organic compounds (VOCs) of Michelia champaca flowers at different developmental stages were studied.【Method】The petals of M. champaca at different developmental stages were used as materials to investigate the components and their changes of volatile organic compounds (VOCs) by using the methods of headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS).【Result】Fifty-one volatile compounds were identified from petals during the whole flowering process of M. champaca, of which, 1,6-cyclodecadiene, 1-methyl-5-methylene-8-(1-methylethyl)-, [s-(E,E)]-, cyclohexane, 1-ethenyl-1-methyl-2,4-bis(1- methylethenyl)-, [1S-(1.alpha., 2.beta.,4.beta.)]-，1,6-octadien-3-ol, 3,7-dimethyl-，benzoic acid, methyl ester , beta-pinene and Eucalyptol were the major volatile compounds emitted from M. champaca flower. The relative content of different volatile compounds emitted from M. champaca flower showed different trends during flowering. The relative content of cyclohexane, 1-ethenyl-1-methyl-2,4-bis(1- methylethenyl)-, [1S-(1.alpha.,2.beta.,4.beta.)]-, benzoic acid, methyl ester and ylangene increased at first and then decreased, while the beta-pinene, 1,3,6-octatriene, 3,7-dimethyl- and eucalyptol showed crosscurrent, and the relative contents of caryophyllene, alpha -cubebene and 1,5-cyclodecadiene, 1,5-dimethyl-8-(1-methylethylidene)-, (E,E)- declined during the flowering process. 【Conclusion】The volatile compounds and their contents were distinctly different at different developmental stages of M. champaca flowers, the major components had officinal and health care effect. So, M. champaca is an excellent ornamental species for building plant landscape that is beneficial to people's health.

Key words: Michelia champaca, flowering, SPME, VOCs