The hydroliquefaction of Illinois No. 6 coal with petroleum atmospheric residue (AR), hydrogenated AR and coal-derived recycled oil was carried out using an oil-soluble Mo catalyst and a Ni-Mo-alumina catalyst. The liquefaction using the oil-soluble Mo catalyst gave lower yields of solvent insolubles than that using the Ni-Mo catalyst. The yields of solvent insolubles during the liquefaction with hydrogenated AR were lower than those with AR, and at the same level as those with recycled oil at 400 degrees C. A synergistic effect is revealed when coal and AR are coprocessed.