In this research, desulphurization of number 6 fuel oil by the H2O2/H2SO4 method was studied. The effects of reaction temperature and reaction time on desulphurization were examined. Also, kinetic approximation for desulphurization was carried out. It was determined that the maximum desulphurization was performed at conditions of reaction temperature of 40 50 degrees C and reaction time of 150 min. The total sulfur content of the fuel oil sample was reduced from 2.78 to 0.68% at the reaction temperature of 50 degrees C and reaction time of 150 min. As the degree of desulphurization increased, the higher heating value decreased at higher reaction temperatures and reaction times. As a result of kinetic approximation, it was found that the order of the reaction was approximately 0.96 and the rate constant, k = 5.84 (*) 10(6) exp(-65.08/RT), for desulphurization of fuel oil by chemical method.