Fe81Al19Tbx (x =0,0.05,0.1,0.2,0.3,0.4) alloys were prepared by a non-consumable vacuum arc melting technique under an inert argon gas atmosphere.The microstructures of the alloys were studied by X-ray diffraction (XRD) and scanning electron microscopy combined with an energy dispersive spectroscopy(SEM/EDS).The magnetic properties and magnetostriction coefficients of the alloys were measured by a vibrating sample magnetometer (VSM) and adifferential resistive strain sensor,respectively.The results show that the Fe81Al19 alloy consists of a single A2 phase with bcc structure,whereas the Tb doped Fe81Al19 alloys are composed of the A2 phase and a small amount of rare earth-rich phase.The doping of the rare earth element Tb makes the Fe81Al19 alloy preferentially oriented along with the crystal direction.With the increase of Tb content,the magnetostriction coefficient of the alloy first increases and then decreases.When x =0.1,the magnetostriction coefficient reaches the maximum,which is 146 ×106.Compared with the as-cast Fe81Al19 alloy (27 × 10-6),it increases by 441％.The enhanced magnetostrictive properties are mainly attributed to the preferred orientation along of A2 phase of the Tb doped Fe81Al19 alloys and lattice distortion caused by the small amount of rare earth atoms entering the Fe-Al alloy lattice.