Epitaxial growth of La0.5Sr0.5CoO3 (LSCO) film has been achieved by pulsed laser deposition. Widely used substrates, MgO, SrTiO3 and LaAlO3, were chosen to examine the effect of the substrates on the growth of LSCO films. The influence of the substrate temperatures (T-s) on the characteristics of the LSCO films was studied in a temperature range of 500-850 degrees C. The LSCO films deposited at substrate temperatures of T-s = 800-850 degrees C show good epitaxial features, better than that of the films deposited at lower T-s. The experimental results reveal that the lattice mismatch and the difference of the expansion coefficients between the substrates and the LSCO films are important in the growth process of the LSCO films.