The effect of TiC particle volume fraction on the electrochemical behaviours of metal matrix composites (MMCs), which is Al-Cu based reinforced with TiCp has been investigated in both aerated and deaerated 1.0 N H2SO4 aqueous solutions. Composites reinforced with TiC particles at volume fractions of 20, 30 and 40% have been produced by conventional hot pressing method and then, artificially aged (T6). The corrosion susceptibilities of the composites have been analyzed by using the cyclic potentiodynamic polarization technique. The surface morphology of the composites has been determined by scanning electron microscopy (SEM). The results show that the corrosion susceptibilities of the composites increase with increased TiC particle content but decreases with T6 heat treatment pet-formed on the composites.