Abstract: The volatile matter from Debregeasia longifolia was analyzed by capillary GC_MS method. By capillary chromatography, 108 peaks were isolated, and 83 compounds of them were identified. The relative percentages of the constituents were determined by GC method. The main chemical components were butylated hydroxytoluene, pentadecane, dibutyl phthalate, 2,6_dimethyl naphthalene, decanoic acid ethyl ester and etc.