In order to demonstrate that light rare-earth(RE)dopants with strong magnetocrystalline anisotropy, whose net moment couples are antiparallel to those of iron, can also induce giant magnetostriction in Gafenol, a light RE element Sm was selected as the third element to dope into Fe_(83)Ga_(17) alloy.(Fe_(83)Ga_(0.17))_(100-x) Sm_x(0≤x≤0.42) ribbons were prepared by melt spinning. The increase of the lattice parameters and saturation magnetization indicates that some Sm atoms enter the A2 matrix substitutionally. Doping the Fe_(83)Ga_(17) ribbons with the light RE Sm element drastically improves the magnetostriction. Perpendicular magnetostriction value of λ_⊥=-5*10~(-4)is achieved in(Fe_(83)Ga_(0.17))_(99.75)Sm_(0.25). It is confirmed that the stronger local magnetocrystalline anisotropy induces larger enhanced magnetostrictions. The greatly enhanced magnetostriction is somehow related to the local microstrains induced by the RE dopants. It is likely that the RE-induced defects in the(Fe_(83)Ga_(0.17))_(100-x)RE_x ribbons function in the similar way as the Ga–Ga pair defects in the undoped Fe–Ga alloys. In order to demonstrate that light rare-earth (RE) dopants with strong magnetocrystalline anisotropy, whose net moment couples are antiparallel to those of iron, can also induce giant magnetostriction in Gafenol, a light RE element Sm was selected as the third element to dope (Fe_ (83) Ga_ (0.17)) _ (100-x) Sm_x (0≤x≤0.42) ribbons were prepared by melt spinning. The increase of the lattice parameters and saturation magnetization indicates that some Sm atoms enter the A2 matrix substitutionally. Doping the Fe_ (83) Ga_ (17) ribbons with the light RE Sm element drastically improves the magnetostriction. Perpendicular magnetostriction value of λ_⊥ = -5 * 10 ~ (-4) is achieved in (Fe_ (83) Ga_ (0.17)) _ (99.75) Sm_ (0.25). It is confirmed that the stronger local magnetocrystalline anisotropy induces larger enhanced magnetostrictions. The greatly enhanced magnetostriction is somehow related to the local microstrains induced by the RE dopants. It is likely that the RE-induced defects in (Fe_ (83) Ga_ (0.17)) _ (100-x) RE_x ribbons function in the similar way as the Ga-Ga pair defects in the undoped Fe-Ga alloys.