The as-cast Cu-doped Fe83Ga17 alloys were prepared by arc-melting.The microstructures and magne-tostrictions of(Fe83Ga17)100-xCux(x=0,3,6,9,12,15)alloys were investigated by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and strain gauge magnetostriction measurement.Vibrating sample magnetometer was employed to investigate the magnetic properties of(Fe83Ga17)100-xCux(x=0,3,6,9,12,15).First-principal calculation was employed to make lattice structure and energy simulation.The results indicate that Cu dopants dissolve into A2 lattice by interstitial doping,which induces tetragonal-like distortion of A2 lattice.And the magnetostriction for Cu-doped Fe83Ga17 alloys is lower than that of Fe83Ga17 alloy.The reduction of magnetostriction is attribute to the increase of Young's modulus caused by Cu dopants dissolve into A2 lattice by interstitial doping and the decrease of magnetoelastic coupling coefficient for Cu-doped Fe83Ga17 alloys caused by Cu dopants dissolve into A2 lattice.