Plasma electrolytic oxidation (PEO) was employed to produce composite coatings containing 200 nm diameter ?-Al2O3 particles on 7075 Al alloy from a silicate base electrolyte. The PEO process was performed under a soft-sparking regime using a pulsed bipolar signal. Different amounts of ?-Al2O3 particles were added into the electrolyte bath. It was found that the incorporation of ?-Al2O3 particles into the coating did not alter the morphology, thickness and roughness of the coatings. However, the ?-Al2O3 particles were detected on the surface of the composite coatings. Corrosion results showed significant improvements in corrosion performance of the composite coatings due to the effective pore blocking provided by the ?- Al2O3 particles which enhances the barrier performance of both inner and outer layers of the coatings. The long-term EIS measurement showed that although the composite coatings reveal higher layer resistances at the earlier times of immersion, but because of the susceptibility to local destruction, they approach to the corresponding values of particle-free PEO coating. Tribocorrosion tests showed that adding 3 g.l-1 ?-Al2O3 particles to the electrolyte bath decreased the lost wear volume of the resulted coating from 30 to 10 mm3 (×10-3). It was concluded that the highest content of ?-Al2O3 particles (i.e. 7 g.l-1) showed adverse effect on both corrosion and tribocorrosion performance of the coatings. Keywords: PEO coatings; ?-Al2O3 particles; corrosion; tribocorrosion; 7075.