We have investigated possible water adsorption forms on stepped Si(111) surface. Calculations have been performed by using the empirical tight-binding method. Two types of adsorption model of water on single layer stepped Si(111) surface have been considered; one of them is the dissociative type (H, OH) and the other is the molecular type (H2O). The total electronic energy and TDOS calculations lead to a dissociative type of adsorption of water on stepped Si(111) surface excluding the molecular type. (C) 1997 Elsevier Science B.V.