Detailed fabrication, structure, and magnetic properties of Fe1-xNix nanowire arrays were investigated. The dependence of structural variation on the Ni content was determined by x-ray diffraction, showing different behaviors of nanowire arrays from the bulk and particle systems. The magnetic properties in the temperature range of 5 to 300 K were studied and results show the coercivity at 300 K does not monotonically decrease as Ni content increases. When the applied field is along the long axis, the temperature dependence of coercivity for Fe0.68Ni0.32 and Fe0.19Ni0.81 nanowire arrays shows a linear decreasing with increasing temperature, which can be understood by a phenomenological nucleate model.