Fatigue behaviour of cast Ni3Al-based alloys with the addition of alloying elements, such as Hf, Zr and Ti etc., has been investigated. It was found that: (1) The alloying elements change remarkably mechanical property and fatigue property of cast Ni3Al-based alloys, in which, the fatigue strenghts of No.1 and No.2 alloys are 215.6MPa and 205.8MPa respectively, while that of No.3 alloy is only 78MPa, for the same cyclic life of 107; (2) Fatigue cracks initiate at the (γ'+γ) /γ interface and “matrix channel” in No.1 and No.2 alloys are at the grain-boundary or micropore, of No.3 alloy often fatigue cracks initiated from the edge of specimen under the cyclic stress; (3) Fbitigue crack propagation of cast Ni3Al-based alloys follows “zigzag” propagation path, and it proceeds through the big blocky (γ'+γ) eutectic and “matrix channel” and along the (γ';+γ)/γ interface in No.1 and No.2 alloys, while the fatigue crack propagation of No.3 alloy sometimes follows the “zigzag” propagation path. Finally, the effect of alloying elements on the fatigue behaviour of cast Ni3Al-based alloys has been discussed.