Thermal simulation experiments on the system of gasoline and magnesium sulfate were carried out using an autoclave operating at high temperature and high pressure in the presence of water. Properties of the gas-oil-solid 3-phase products were analyzed by some advanced analytical methods including gas chromatography, microcoulometry, capillary gas chromatography in combination with a pulsed flame photometric detector, FT-IR and X-ray diffraction. The results showed that the reaction could proceed at 450˚C -550˚C to produce MgO, S, C, H 2 S, CO 2 and a series of organic sulfides such as mercaptans, sulfoethers and thiophenes as the main products. According to the reaction kinetics, the calculated activation energy of the reaction is 68.9 kJ·mol −1 .