A few studies on the synthesis of titanium aluminum nitride (Ti,Al)N films have attracted interests, in particular as an alternative to the widely used TiN films, to obtain wear-protective hard coating with higher oxidation resistance at elevated temperature. Here, the (Ti,Al)N films were prepared by depositing Ti and Al metal vapor under simultaneous irradiation of N ions, that is ion mixing and vapor deposition (IVD) technique. With an increase of evaporation Al/Ti and/or transport ratio (Ti + Al)/N, a single-phase of NaCl structure in the films transformed into that of wurtzite structure through a two-phase mixture consisting of NaCl and wurtzite structure. Based on the revelation of two-phase structure, therefore, the optimum preparation conditions for wear- and corrosion-resistive hard coating were identified. The (Ti,Al)N films were also highly resistant against oxidation. Consequently, the results suggest that the Al oxide layers formed on the top of (Ti,Al)N films during elevated temperature oxidation tests protect the films from further oxidation.