Metal matrix Pt/Al2O3 composite films with 7.5% and 28% volume fraction of Al2O3, respectively, have been prepared by pulsed laser deposition technique on NaCl (100) substrates using Pt and alpha-Al2O3 targets and their structure has been investigated by TEM and X-ray diffraction. The Pt matrix in the composite films grew epitaxially with the orientation relationship Pt (100)parallel to NaCl (100) and Pt[011]parallel to NaCl[010] within the film plane. The Al2O3 particles embedded in the Pt matrix are of gamma-Al2O3 phase with cubic structure. No preferential orientation relationship between gamma-Al2O3 and Pt can be defined. The size of the gamma-Al2O3 particles in the film has been determined and the origin of the observed microstructure has been analyzed.