Abstract: The chemical components of volatile oils from Yellow Chrysanthemum morifolium during flower development stages were identified by GC-MS, and the relative content of each component was determined by peak area normalization methods. The DPPH free radical scavenging activity of the volatile oils was determined by ultraviolet spectrophotometer. The results were as follows:the components and contents of essential oils in Yellow C.morifolium flowers were significantly different among different flower development stages. There were 40, 43, 45 and 35 compounds, identified at squaring stage, slight open stage, bloom stage and late bloom stage, respectively. In total, 67 components were identified from the volatile oils of four different development stages including olefin hydrocarbon(36), alcohols(18), ketones(2), esters(4), aldehydes(3) and oxides cervidae(4). Twenty-two common compounds were detected in Yellow C.morifolium during flower development stages. The numbers of special components among four periods were 5, 6, 8 and 5 compounds, respectively. The contents of olefin hydrocarbon, alcohols, ketones and esters were high, which were the main components at during flower development stages, nevertheless the specific components and their contents were distinctly different at these stages; The ability of scavenging DPPH radicals of the volatile oils was stronger than that of Vc, and the volatile oils showed strong antioxidant activity.

Key words: Yellow Chrysanthemum morifolium, development stage, volatile oil, GC-MS, antioxidant activity