A process for producing a pitch which is used as a raw material for producing carbon fibers is disclosed. The process comprises subjecting a petroleum heavy residual oil to hydrogenation treatment in the presence of catalysts, removing a low boiling point fraction of the oil by reduced pressure distillation, subjecting the resulting reduced pressure distillation residual oil to solvent extraction treatment, and carrying out thermal modification of the resulting extraction component.By utilizing the process for producing the pitch it is possible to use a wide variety of different types of oils in order to produce carbon fibers. The carbon fibers produced from the pitch produced according to the disclosed process have desirable characteristics.