A dual metal Ni-Mo/gamma-Al2O3 catalyst was prepared by saturated impregnation and H-2 reduction pretreatment on gamma-Al2O3 support with Ni as the active component and Mo as the promoter. The support and catalysts were characterized using x-ray diffraction, hydrogen temperature-programmed reduction, and scanning electron microscopy. The catalytic properties for the reaction of dibenzothiophene (DBT) were investigated in a high-pressure reactor. The hydrodesulfurization (HDS) activity was comparable with those of advanced desulfurization catalysts FHUDS-5 and FHUDS-6. The Ni-Mo catalyst had excellent dispersion characteristics on the support. Synergism between Ni and Mo was greatest at a Ni/Mo molar ratio of 2:1. The DBT conversion on Ni-Mo/gamma-Al2O3 catalyst reached 100% at a reaction temperature of 300A degrees C, pressure of 4 MPa, and reaction time of 150 min. The Ni-Mo/gamma-Al(2)O(3)atalyst was significantly more active than the aforementioned two commercial FHUDS catalysts for HDS of DBT.