The microstructural evolution of the BaTiO3 films grown on (001) MgAl2O4 spinel substrates at different temperatures by means of pulsed laser deposition technique is studied via transmission electron microscopy (TEM). The BaTiO3 film grown at 850 degrees C consists of columnar grains of random orientations. Once the substrate temperature is over 900 degrees C, the BaTiO3 films grow on (001) MgAl2O4 substrates epitaxially. The cross-sectional TEM study reveals that the boundaries and interfaces act as the sources to emit stacking faults and twins which are detrimental to the film quality. The quality of epitaxial films increases with the growth temperature, and is optimized at the growth temperature of 1050 degrees C. The evolution of film microstructures with the growth temperature is discussed in view of the growth temperature, the surface structure of MgAl2O4 substrates, and the phase transition of BaTiO3. (c) 2006 Elsevier B.V. All rights reserved.