In order to improve economics of coal liquefaction process, it is important to make light oil in a high yield. In this paper, effects of the boiling point range of solvent to increase lighter oil fraction were studied using an autoclave and a continuous BSU. According to heavier solvent recycled, the ratio of light fraction yield in total distillate increased, but the fraction to be recycled as solvent was shortage. An addition of coal liquid bottom (CLB) showed large effect to increase both lighter fraction and solvent fraction combined with the recycle solvent whose boiling point range was 300 to 420℃.
