Abstract CoFeP alloy nanowire arrays have been fabricated by autocatalyzed electroless deposition in an anodic alumina membrane (AAM). The images of CoFeP nanowire arrays and single nanowires are obtained by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. Selected area electron diffraction (SAED), X-ray diffraction (XRD) and energy dispersive spectra (EDS) are employed to study the morphology and chemical composition of the nanowires. The results indicate that CoFeP nanowire arrays are amorphous in structure. The magnetic property of alloy nanowire arrays is characterized by using a vibrating sample magnetometer (VSM). The hysteresis loops show that the easily magnetized direction of CoFeP is parallel to the nanowire arrays and that the CoFeP nanowire arrays have obvious magnetic anisotropy as a result of the shape anisotropy. Compared with the electrodeposition method, autocatalyzed electroless deposition needs neither a supply of power nor a sprinkling of gold on one side of the AAM before the deposition and some defects of electrodeposition can be overcome.