In this paper, we reported the oxidation behaviour of Ti ₂AlN films on polycrystalline Al ₂O ₃ substrates. The Ti ₂AlN films composed mainly of nanolaminated MAX phase was obtained by first depositing Ti-Al-N films using reactive sputtering of two elemental Ti and Al targets in Ar/N ₂ atmosphere and subsequent vacuum annealing at 800 °C for 1 h. The Ti ₂AlN films exhibited excellent oxidation resistance and thermal stability at 600-900 °C in air. Very low mass gain was observed. At low temperature (600 °C), no oxide crystals were observed on film surface. Blade-like θ-Al ₂O ₃ fine crystals formed on film surfaces at 700-800 °C. At high temperature (900 °C), firstly θ-Al ₂O ₃ formed on film surface and then transformed into α-Al ₂O ₃. At 700-900 °C, a continuous Al ₂O ₃ layer formed on Ti ₂AlN films surface, acting as diffusion barrier preventing further oxidation attack. The mechanism of the excellent oxidation resistance of Ti ₂AlN films was discussed based on the experimental results.