Abstract: The effect of FCC gasoline selective hydrodesulfurization and the operation cost at different reaction temperature were analyzed. It is concluded that the lower reaction temperature is better for reducing RON loss and that the process of FCC gaosoline hydrodesulfulization followed by sweetening unit is good for lowering sulfur content of the final product to less than 10 ?g/g and at the same time for reducing the operation cost and prolonging the catalyst service life.