• Oxidation behavior of Ni-Al-Hf alloys with different phases is studied. • The distributions of HfO 2 are different in scales on Ni-Al-Hf alloys. • HfO 2 is distributed linearly within the scale on single β-phase Ni-49.9Al-0.1Hf. • For Ni-25Al-0.1Hf and Ni-33Al-0.1Hf, HfO 2 appears along the spinel/Al 2 O 3 interface. • Formation mechanisms of HfO 2 with various distributions are discussed. HfO 2 tends to grow on Hf-containing alloys during high-temperature oxidation and significantly affects the oxidation resistance. In this paper, cyclic oxidation behavior of single β-phase Ni-49.9Al, γ’-phase Ni-25Al and binary phase (γ’+β) Ni-33Al alloys doped with Hf was investigated at 1100 °C. HfO 2 was located at different positions of the oxide scale grown on the above alloys. The HfO 2 was distributed linearly within Al 2 O 3 scale in Ni-49.9Al-0.1Hf whilst HfO 2 primarily appeared along the spinel/Al 2 O 3 interface in Ni-25Al-0.1Hf and Ni-33Al-0.1Hf. In addition, the specific distribution of HfO 2 in Ni-33Al-0.1Hf was analyzed by HAADF-STEM and the corresponding formation mechanisms were proposed.