The unique properties of nanowires compared with their bulk counterparts can be attributed to their large surface-area-to-volume ratio. The mechanical properties of Ni3Al alloys nanowires have been studied at high temperatures using molecular dynamics simulations. MD simulations have been carried out on Ni3Al metallic alloy with face-centered cubic (FCC) lattice upon application of uniaxial tension at Nanoscale. A many-body interatomic potential within the second-moment approximation of the tight-binding model (the Cleri and Rosato potentials) was employed to carry out. MD simulation used to investigate the effect of temperature of Ni3Al nanowire on the feature of deformation and fracture. Temperature effect on the extension property of metal nanowire is discussed in detail. The mechanical strengths and the mechanical strain of the nanowires decrease linearly with the increasing temperature. The feature of deformation energy can be divided into four regions: quasi-elastic, plastic, flow and failure. Experiments have shown that when the temperature increases the first stage of deformation was narrowed, and the second stage was widened. The results showed that breaking position depended on temperature. The simulation results at Nano-scale play an important role on the mechanical behaviors of nanostructure. The yield stress of Ni₃Al metallic alloy is found to be 100 times higher than that of the corresponding bulk metals. The yield strain and fracture stress of Ni₃Al metallic alloy are also found to be significantly higher compared with those of the bulk metals. The influence of deformation mechanisms on the mechanical properties of FCC Ni₃Al metallic alloy was discussed.