This study investigated the characteristics of slurry-phase hydrocracking of vacuum residue (VR > 524 degrees C) at a high conversion (40-95 wt.%) with a change of reaction temperatures and concentrations of the dispersed molybdenum (Mo Conc. 100-2000 wt.ppm) catalyst. Experiments were carried out with an initial hydrogen pressure of 80 bar (at 80 degrees C) at a reaction temperature from 385 to 440 degrees C for four hours in a batch reactor. As results, it was found that the sediment formation is mainly dependent on the VR conversion by the reaction temperature and started over 70 wt.% of VR conversion. Up to 70-80 wt.% of VR conversion, the higher catalysts showed the higher asphaltene conversion and prevented the sediment formation at the boundary of its formation, but it didn't show any effect over 80 wt.% of VR conversion anymore. Based on the analysis of the structural change and xi-potential of asphaltene from the liquid and sediment, and SARA compositional change in the liquid, the reason for sediment formation was explained.