Abstract: The volatile components in Toona sinensis buds at different growth stages and it different parts were analyzed by
headspace solid-phase micro-extraction and gas chromatography-mass spectrometry (GC-MS). The results obtained were
as follows: (1) there were 35 components identified at stage Ⅰ, 17 at stage Ⅱ, 22 at stage Ⅲ, 15 at stage Ⅳ, 12 at stage
Ⅴ and 16 at stage Ⅵ. With the growth of T. sinensis, the relative contents of carbonyls, sulfur, alcohols were increased at
first and then decreased, while vinyl showed just the opposite trend. Hydrocarbons and the other compounds were gradually
decreased; and (2) 26 components were found to be present in the upper part, 19 in the middle part, and 12 in the lower part
of buds with sulfur-containing compounds comprising 72.15%, 88.33% and 88.59% of the total volatiles, respectively, which
were confirmed as the main aroma components of T. sinensis. The middle part was suggested as the main releasing part
according to the relative content of the characteristic aroma component 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene.

Key words: Toona sinensis, growth stage, part, aroma components, headspace solid-phase microextraction