We report the structure and electronic properties of AgmPdn bimetallic clusters (m, n = 1-2) in gas phase and deposited on the alpha-Al2O3(0001) surface using plane wave pseudopotential approach. The ground state geometry of the mixed clusters is significantly modified after deposition. For Ag2Pd2 tetramer, the gas phase compact tetrahedron structure reorients to open bent rhombus. The charge distribution analysis shows that small amount of charge is accumulated at the Pd site and depleted at the Ag site. The electronic density of states analysis reveals that after deposition, the bands near the Fermi energy become wider. (C) 2012 Elsevier B.V. All rights reserved.