NiAl coating obtained by pack aluminization is the firstly used as Al

2

O

3

-forming high-temperature coating. Since the middle of the last century

NiAl coatings were employed in hot sections of aero-engines for protection against high temperature oxidation. Investigations of the oxidation mechanisms of the coating

and exploration of the coating techniques continue up to now. On a basis of understanding to the oxidation mechanism of alloys and thermal growth of Al2O3

a concept of improving the oxidation resistance of nickel aluminide coating by means of grain refinement and typical metal oxide dispersions has been proposed. Meanwhile a method to refine the grains of the nickel alumin

ide coating and disperse it with metal oxide nanoparticles has been presented

and key factors (including growth rate of the Al

2

O

3

scale

Al

2

O

3

phase transformation from metastable phases to the stable phase

the Al

2

O

3

adhesion to the coating as well as the interdiffusion between the coating and the metal substrate) intrinsically correlated with the oxidation resistance of the coating which can be significantly affected by its modification in microstructure and chemical composition have been reviewed. The new result is expected to be helpful to further offer theoretical and experimental bases for tapping the potential and prolonging the service life of the aluminized coatings in application.