In this work, we investigate the adsorption of Au-8 cluster onto H-terminated Si(100):2 x 1 asymmetric surface by density functional theory within local density and generalized gradient approximations. We study the site-dependent shape of Au-8 cluster, adsorption energies, band structures and the corresponding charge distribution. We show that the electronic properties of the cluster and substrate complex change with the location of the cluster on the surface. (C) 2009 Elsevier B.V. All rights reserved.