Abstract: An oil-soluble catalyst with 5.44w% Mo was synthesized. UV and IR analysis show that the synthetic products have the objective organic group. The experiments indicate that the catalyst is oil soluble and insoluble in water. Influence of reaction temperature, pressure and catalyst concentration on hydrogenation activity of Venezuela heavy oil in slurry bed reactor was simulated by autoclave. It is found that hydrogenation activity for slurry-bed hydrocracking of Venezuela inferior heavy oil is increased by adding oil-soluble catalyst. Under the conditions of catalyst concentration 200μg/g, temperature 430℃ and hydrogen pressure 8.0MPa, the maximum light oil yield per unit of coke could be up to 42.69%.