PURPOSE: To liquefy coal, economically, in an industrial scale without formation of high molecular weight pitch, by thermally treating and hydrogenating a cracked petroleum fraction, and thermally treating coal powder under specific conditions by using the above product as the solvent.

CONSTITUTION: The fraction having an initial boiling point of ≥150°C, contained in the oil prepared by thermal cracking, steam cracking or catalytic cracking of petroleum at ≥700°C, is thermally treated at 250W500°C for 15min to 10hr under normal pressure to 200kg/cm2G. The aromatic nuclei of the thermally treated product or of its distillate are partially hydrogenated in the presence of a hydrogenation catalyst. 1W10 Parts by weight of the hydrogenated product or its mixture with a coal-originated heavy oil is mixed as a solvent with 1 part by weight of coal powder. The mixture is treated at 300W500°C for 0.5W5hr under normal pressure to 200kg/cm2G to liquefy the coal.