CoNiCu magnetic alloy nanowires were prepared in AAO templates by a pulse electrochemical deposition method. XRD measurements show that there are four magnetic phases in the nanowires, Co, Ni, NiCu and CoCu. The measured magnetic hysteresis loops taken along two directions (H is applied along or perpendicular to its longitudinal direction) show that the CoNiCu nanowire array has a weak anisotropy. The composites of magnetic alloy nanowires and wax have a good electromagnetic wave absorption property of GHz frequency. When the thickness of the absorbing coating is 4 mm, its minimum reflection loss can reach to –30 dB.