Carbon nanotubes (CNTs) have been synthesized directly on the electrically conducting nickel substrate without additional catalyst. Field emission properties of the as-prepared sample were characterized using parallel plate diode configurations. It was observed that the field emission qualitatively follows the conventional Fowler-Nordheim (F-N) theory from the straight line of 1n(I/V-2) versus 1/V plot at the high applied field region. The uniformity and stability of the electron emission have also been examined. The low electron turn-on field (E-10) and high emission current density indicates the potential applications of this new CNT-based emitter. (c) 2006 Elsevier B.V. All rights reserved.