Three kinds of coals with different rank of 76, 85 and 87C% were hydrocracked to study the specific reaction behavior of four kinds of 1coal liquefaction catalysts such as CuCrO4, Fe2O3+S, MoO3-TiO2 and MoS3-Al2O3. The reaction was conducted without any solvent to find out the specific phenomenon of each combination of coal and catalyst, and terminated at the point where nearly 30% of an initial amount of coal is converted to benzene-soluble. The products were separated by GPC into four fractions, and their average molecular weights and intrinsic viscosities were measured to study characteristics of each combination. As a result, the molecular weight distribution was obviously dependent on the combination of coal and catalyst, and no specific relation was observed between the molecular weight and intrinsic viscosity. The molecular of each fraction had a bar shape with an elliptic section indicating no apparent correlation with the molecular weight. 3 refs., 1 figs., 2 tabs.