To decrease the sulfur content of a gasoline fraction down to a low level without yield loss of gasoline by fractionating crude gasoline into the light fraction and the heavy fraction, treating the light fraction with hydrogen followed by stripping.
Crude gasoline is fractionated into the light fraction which contains more than the half of olefins and mercaptans and boils at ≤210°C and the heavy fraction. The light fraction is subjected to hydrogenation treatment in the presence of hydrogen using a catalyst containing a metal in group VIII and a metal in group VI at 160-380°C under the pressure of 5-50 bar and then stripped to remove hydrogen sulfide. Further, the light fraction is treated with hydrogen in the presence of a 0.1-1% palladium on carrier catalyst at 50250°C and 4-50 bar. Then, the product is subjected to sweetening treatment with an oxidizing agent, a catalyst, and an alkaline base whereby a gasoline of low sulfur content is obtained.