The catalysts of the XMo6(S)/Al2O3 and Ni-3-XMo6(S)/Al2O3 structures were prepared from heteropoly-compounds (HPCs) of Anderson type (where X = Co, Ni, Cr, Mn. Fe, Cu, Zn, Ga). The precursors and synthesized catalysts were characterized by FTIR, XRD, EXAFS, HRTEM techniques. The prepared catalysts were examined in model reactions of thiophene HDS and benzene HYD and in hydrotreating (HDT) of diesel fraction. The correlations between the catalytic activities in HDS and HYD and the heats of thiophene adsorption depending on the nature of the heteroatom prove that it plays an important role in the formation and behavior of the HYD and HDS active sites. It was found that heteropolycompounds are effective precursors of a multilayered active phase of hydrotreating catalysts. to (C) 2010 Elsevier B.V. All rights reserved.