Co Fe P alloy nanowire arrays have been fabricated by autocatalyzed electroless deposition in an anodic alumina membrane (AAM). The images of Co Fe P 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 Co Fe P 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 Co Fe P is parallel to the nanowire arrays and that the Co Fe P 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.