Abstract: Flash gas chromatography (FGC) was applied to the analysis of burned residues of 2 natural fibre wood and cotton mixed with gasoline and diesel oil separately under simulated condition of scene of a fire. On the base of the results of thermogravimetric analysis of the burned residues, flash temperature for GC analysis was set at 300℃. Burned residues of wood and cotton with and without the addition of the 2 burning-supporters (i.e., gasoline and diesel oil) and with their sampling time of 0, 24, 72 h after naturally gone out of burning, were taken as the analytes for FGC analysis. It was shown by the testing results, that 1 characteristic components of the burning supporters could be detected from the chromatograms given by FGC, giving a strong base for identification of the burning supporter; 2 with delaying of time of sampling, due to volatilization of the burning supporter, decrease of the characteristic components remained was observed; 3 the burned residue of cotton, showed better effectiveness in reserving the characteristic components of burning supporter as compared with the burned residue of wood; and 4 the characteristic components of diesel oil remained after burning showed a longer time of reserving as compared with gasoline.