Ordered ferromagnetic–antiferromagnetic FeMn nanowire arrays were successfully fabricated by alternating current (AC) electrodeposition in to nanoporous alumina templates (AAO). This membrane was fabricated with two-step anodizing method. The effect of electrodeposition frequency on the properties and microstructures of FeMn nanowires was investigated. Different alloy nanowires were prepared with 50, 100, 200, 400, 600, 800, and 1000 Hz electrodeposition frequencies. The coercivity of alloy nanowires was increased from 614 to 1490 Oe by increasing of electrodeposition frequency.