Ni nanowire arrays were prepared by electrodeposition into nanopoures of anodic alumina template using a two-electrode electrochemical cell. The morphology of the samples was investigated by means of scanning electron microscopy (SEM). The microwave absorption characteristics of the samples were examined using an HP network analyzer. The results show that the arrays of nickel nanowires are 66 nm in diameter. Microwave absorption spectra of the Ni nanowire/paraffin composite were measured in the frequency range of 12-18 GHz. The electromagnetic wave reflection loss values of the Ni nanowire/paraffin composite sample are lower than -20 dB when the thickness of the nanowire/paraffin composite is adjusted, and an optimal reflection loss value of -40.2382 dB is obtained at 14.356 GHz with an absorber thickness of 1.8 mm, suggesting that the nickel nanowire composites are promising candidates as microwave absorbers.