PURPOSE: To obtain a light gas oil base material excellent in hue in high yields by mixing a vacuum gas oil with a light cycle gas oil, hydrodesulfurizing the obtained desulfurizing base oil and fractionating the product of hydrosulfurization.

CONSTITUTION: A vacuum gas oil obtained by vacuum-distilling crude oil is mixed with 2-70wt.% light cycle gas oil obtained by hydrodesulfurizing the vacuum gas oil and successively executing the fluid catalytic cracking, the obtained desulfurizing base oil is hydrodesulfurized, and the obtained oil is fractionated. In the hydrodesulfurization of vacuum gas base oil for obtaining the light cycle gas oil, tungsten, nickel or the like is used as the hydrogenation catalyst, and in the fluid catalytic cracking of the formed oil, for example silica alumina or zeolite catalyst is used.