The specific adsorption sites at the initial growth stage and the atomic structure of AlN on the SrTiO3 (1 1 1) substrate have been systematically investigated. The Al adsorption atoms are more favorable than the N atoms for the SrTiO3 (1 1 1) surface. The abnormal Al/SrO3 interface is energetically favorable among the atomic arrangements of the AlN/SrTiO3 (1 1 1) interfaces. Oxygen vacancies at the abnormal Al/SrO3 interface weaken the stability and induce the occupied states. (C) 2012 Elsevier B.V. All rights reserved.