Abstract CoFe 2O 4 nanowire arrays with an average diameter of about 40 nm were prepared in porous anodic aluminum oxide (AAO) template using sol–gel process. Transmission electron microscopy (TEM) diffraction pattern and X-ray diffraction (XRD) showed that the nanowires were polycrystalline phase. Magnetic measurements showed the arrays of nanowires did not show a preferential magnetic orientation, the reason was briefly discussed. The effect of heating rate on the structure and magnetic properties of CoFe 2O 4 nanowire arrays was investigated. The result showed that the coercivity decreased with the increase of the heating rate.