Abstract: The chemical composition of the top note of Osmanthus in Hangzhou has been studied by using the adsorption desorption method.By means of GC/MSin conbination with Kovat's Retention Index for qualitative determination 58 compounds including mainly β-ocimene-X 1-mcthyl-6-isopropylidene bicyclo [3,1,0] hexane and β-ocimene-γ were identified.As compared with the published components in Osmanthus absolute oil,52 compounds were additionally identified in the top note of Osmanthus in our study.Besides,3-methyl pyrazole and 3,4-dimethyl-2-pyrazole-5-one were also identified,which were rarely found in aroma of plant materials.