The structures and the epitaxial growth behavior of the La0.5Sr0.5CoO3 thin films prepared by pulsed laser deposition on various substrates and at different deposition temperatures have been studied systematically.Epitaxial growth of the LSCO thin films with low resistivity and metallic conducting features has been demonstrated on the substrates of LaAlO3,SrTiO3 and MgO.Studies reveal that for the epitaxial growth of LSCO thin films,700—800℃ are the optimal deposition temperatures and LaAlO3 is the optimal substrate.Emphases are laid on the discussions of the influences and the mechanisms of substrates and deposition temperatures on the epitaxial growth of the LSCO thin films.