Abstract: The behaviors on heating of 9 kinds of domestic bitumen with or without the addition of NaNO3, before and after γ-irradiation, are studied by means of DTA(differential thermal analysis), TGA (thermogravimetric analysis), gas chromatographyand IR-spectroscopy. It is shown that for the system NaNO3-bitumen, heat evolutionbegins at a little bit over 220℃, and it is believed that this is due to oxidation reaction that occurs in this system. Some other factors that influence the combustion of this system are studied and a margin of temperature is recommended for the safe handling and operation of this system.