Abstract: The ribbons of Mn₅₀Ni₃₈In₉Co₃, Mn₄₉Ni₃₈In₉Co₃Cu₁ and Mn₄₇Ni₃₈In₉Co₃Cu₃ alloy ribbons were prepared by melt-spinning technology.The microstructure, martensitic transformation behavior and hysteresis loss of the ribbons were analyzed.The results show that with the increase of Cu content, the martensitic transformation temperature increases gradually, and the hysteresis of phase transformation and the hysteresis loss decrease.This is because Cu element can promote the improvement of geometrical compatibility of the alloy lattice.