The catalyst activities and the grinding characteristics of natural iron compounds and sulfides were investigated with the aim of preparing an industrial coal liquefaction catalyst for the NEDOL process large-scale plants. From the viewpoint of economy, since these plants are to be located at coal mining sites, it is economical to utilize a natural compound produced in the vicinity of plant site as the catalyst raw material. The coal liquefaction, using an electromagnetic agitation type autoclave, suggested that iron sulfide (pyrite) is the best raw material for the catalyst, because it contains higher iron and sulfur for producing pyrrhotite, an active component under the reacting conditions, and thereby, it needs no pollutant sulfur addition. However, taking into consideration the grinding characteristics, iron sulfide is not thought to have good grinding characteristics in a fine particle zone. Co-pulverization, using iron sulfide and coal, improves the grinding efficiency, the abrasion and the catalyst activities, so that the industrial catalyst preparation can be realized by means of the co-pulverization method.