The adsorption of thiophene on promoted MoS2 cluster-model catalysts has been investigated by using the density functional theory (DFT) method. The promoted MoS2 cluster-model has been prepared by replacement of the central Mo atom on (3 0 (3) over bar 0) plane of a Mo16S32 cluster with a first-row transition metal (Cr, Fe, Co, Ni, Cu, and Zn). There is a volcano-type relationship between the calculated adsorption energy of thiophene and the experimental HDS activity, meaning that a moderate interaction between active sites and thiophene is important for HDS activity. The present work provides the direct relationship between the interaction of reactants to active sites and HDS activity, and helps to estimate the HDS activity of promoted MoS2 catalysts. (C) 2003 Elsevier B.V. All rights reserved.