Abstract: A process for producing a pitch useful as a raw material for carbon fibers, which comprises(1) heat-treating at least one starting material selected from the group consisting of a heavy oil obtained by fluid catalytic cracking of a petroleum, a distillate or a residual oil obtained by distilling the heavy oil, and a pitch obtained by heat-treating any of the foregoing materials at a temperature of 350.degree. to 550.degree. C.,(2) separating and removing insoluble substances from the reaction mixture obtained in step (1) to obtain a first treated mixture,(3) heating the first treated mixture obtained in step (2) at a temperature of 250.degree. to 400.degree. C. and removing light fractions which distill at said temperature to obtain a second treated mixture, and(4) treating the second treated mixture obtained in step (3) at a temperature of 430.degree. to 550.degree. C.