PURPOSE: To obtain pitch useful for preparing especially carbon fiber, having a low softening point and improved spinnable properties, by using a heavy oil obtained by fluid catalytic cracking of petroleum, etc. and a residual oil fraction of hydrogenation product of petroleum heavy oil as raw materials.

CONSTITUTION: A mixture of (A) a heavy oil having ≥200°C boiling point obtained by fluid catalytic cracking or thermal cracking and (B) a residual oil fraction of a formed oil obtained by hydrogenating a petroleum heavy oil is heat-treated at 350W450°C (preferably at 380W420°C), to give pitch usually containing 30W80wt% mesophase, from which pitch substantially containing 100wt% mesophase is separated. A heavy oil having 200W450°C boiling point among a reaction product obtained by fluid catalytic cracking of gas oil, normal-pressure residual oil, etc. in the presence of a silica alumina catalyst, etc. at 450W550°C may be cited as the component A.