The effects of Ar+ ion sputtering on the surface of NiAl(110) and its oxidation behaviors were investigated using XPS and LEED. The surface roughness increased and the surface aluminium concentration decreased after several times of cleaning and oxidation of the NiAl(l 10) surface. This surface was shown to be less reactive under 1020 K oxidation but more reactive under 500 K than the first-cleaned NiAl(110) surface. After heating the samples with oxide over-layer to about 1320 K for about 15 min, the oxide over-layer was completely disappeared and a clean NiAl(110) surface was obtained. This result provided a new way to clean the NiAl(110) surface. (C) 2004 Elsevier B.V. All rights reserved.