Abstract: A series of zeolite-based hydrocracking catalysts was prepared using modified Y-zeolite and alumina as support. Nickel, tungsten (NiW) and Nickel, Molybdenum (NIMo) metal pairs were used as active metals. The metals were added using incipient wetness impregnation method. Commercial Y-zeolite active was modified by steam treatment at various temperatures and the unit cell size was measured by XRD method. Two sets of catalysts were prepared using modified Y-zeolite and γ-alumina in a ratio of 50:50 and 30:70 respectively. The metal pair loaded on each type of support used was eighter NiMo or NIW. The objective of the study was to investigate the effect of active metal type and the acidity function on the catalytic activity. The prepared catalysts were characterized by surface area, pore volume, Temperature programmed-Desorption (TPD) of ammonia and Temperature Programmed-Reduction (TPR). The hydrocrcking activity was measured using cumene as a model compound. It was observed that NiW- based catalysts were more active in hydrocracking of cumene than were NiMo-based catalysts. The results of TPD of ammonia are not directly correlated with the conversion of cumene, indicating that the Lewis acid sites from γ-alumina are contributing more to the total acidity measure by TPD of ammonia. The hydrocracking activity of the prepared catalysts was also measured using vacuum gas oil as feed in a batch autoclave reactor. All of the prepared catalysts showed good activity in comparison with a commercial hydrocracking catalysts. However, a clear difference in conversion performance could not be obtained under the conditions the catalysts were tested in the batch reactor.