Epitaxial growth of the La0 3Sr0 5CoO3(LSCO) thin films has been realized on LaA103, SrTiO3 and MgOsubstrates by pulsed laser deposition. The epitaxial growth behavior and the electrical transport properties of these filmswere studied systematically. The temperature dependencies of the resistivity of the film have been determined. Studiesindicate that close dependencies exist between the crystal structures and the electrical transport properties of the epitaxialLSCO films, and that the epitaxial thin films are of low resistivity and metallic conductive features. The epitaxial filmsdeposited on the LaAl03 substrates at about 700℃ possess the optimal properties compared with the others. Discussionsof the dependencies and the mechanisms of the epitaxial structures on the electrical transport properties of the LSCO filmshave been made