Abstract: Ceramic coatings on Al alloys were prepared via. micro arc oxidation process using natural rock (10 g/L fired and unfired porcelanite) and (2.4 g/L) nano-TiO2 additives. The phase composition, microstructure (SEM and EDX), micro hardness, thickness, roughness and wear resistance of the coatings were studied. The results showed that the thick and hard (γ-Al2 O3 ceramic coatings can be deposited by MAO process on Al alloys using electrolytes contained fired porcelanite with modified tribological properties and less porosity and its non-uniform distribution in the structure. The addition of nano-TiO2 recorded the highest hardness and reduced the pore size and tunnels in coatings structure.