Oxidative desulfurization of gasoline was conducted in emulsion oxidative system (water –in-oil [W/O]) using hydrogen peroxide as the oxidizing agent, N-methyl-2-pyrrolidone (NMP) and water as extractive solvent, span60 as surfactant. Phosphomolybdic acid / activated semi-coke (30 wt%)were prepared by impregnation. These catalysts were characterized by scanning electron microscope (SEM). The effect of amount of catalysts, on the efficiency of desulfurization was investigated. Under this operation condition, the sulfur level of the desulfurized gasoline can be lowered from 550 ppm to below 80 ppm after oxidation and extraction. In addition, the gasoline after oxidation and extraction were analyzed by GC-FPD for sulfur content.