Soaking coal in coal liquids at 300-400[degrees]C (high-tenperature soaking) has been studied for coal dissolution prior to liquefaction in the previous task. Two high-volatile bituminous coals, Illinois No. 6 and Pittsburgh No. 8, were examined in three different coal liquids. The high-temperature soaking was effective to solubilize more than 70 wt% cf these coals. The mechanism of disintegration of coal by the high-temperature soaking was investigated under various soaking conditions. The products was also analyzed with solvent swelling. These results were rationalized that coal is solubilized primarily by physical disintegration. The derived mechanism was consistent with the new concept of coal structure: A significant portion of coal is physically associated, not three-dimensionally cross-linked. Radically-induced scission reactions were proposed to prorate breakage of coal moleculs by the combination of the high-temperature soaking before liquefaction. In this term, the effect of radical initiators were investigated under the conditions of the high-temperature soaking and liquefaction. Illinois No. 6 coal and a coal liquid derived from the same coal were used. The first section reports the effect of radical initiators on coal disintegration, and the second section reports the effect of a radical initiator on coal liquefaction. Radical initiators had a positive effect on disintegration. However, the effect was highly temperature-dependent and had a negative effect on liquefaction at high tenperatures.