A comparative study on the structural and magnetic properties of Co and Co71Ni29 nanowire arrays prepared by AC electrodeposition in alumina templates has been presented. The Co and Co71Ni29 nanowires observed by SEM and TEM have a 45 nm diameter and exhibit high aspect ratio. Also, the nanowires of both Co and Co71Ni29, determined by XRD, have an identical crystallographic structure. The Co71Ni29 nanowires exist in a cobalt solid solution. Both the as-obtained Co and Co71Ni29 nanowire arrays measured by VSM show obvious magnetic anisotropy, dominated by shape anisotropy. Compared to the Co nanowire arrays, Co71Ni29 nanowire array shows an enhanced coercivity Hc (perpendicular to) and approximate square ratio Mr/Ms(perpendicular to).