This study investigated how lattice strain affects the surface morphology of La0.7Sr0.3MnO3 (LSMO) epilayers on SrTiO3 (STO) substrates by X-ray scattering and atomic force microscopy (AFM). Almost pseudomorphic growth of LSMO epilayers is observed up to a thickness of 300 angstrom on an STO substrate. The Jahn-Teller strain in the LSMO lattice increases as the epilayer thickness falls. The dynamic roughness exponent of the rapid roughening regime associated with the strain relief is similar to 1.029. Variations in magnetic and transport properties of LSMO epilayers are discussed with reference to changes in the lattice strain in the LSMO epilayers. (C) 2007 Elsevier B.V. All rights reserved.