This paper presents results of plasma oxidizing of aluminium alloy which was carried out in a low-frequency pulse excited plasma. The processing temperature was about 450 degrees C and the processing time was 3 h. The modified layer was characterized by X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. Atomic force microscopy and scanning electron microscopy observations indicated that no evident defects appeared on the surface of the oxidation layer. Immersion experiments in 3.5% NaCl solution were carried out to test the effect of plasma oxidation on the corrosion resistance of surface oxidized aluminium alloys. After immersion for 200 h, the severe corrosion occurred on the untreated sample Surface while no evident corrosion was observed for the treated sample. (C) 2008 Elsevier B.V. All rights reserved.