Abstract: In this paper, Nanotubes films are grown by thermal chemical vapour deposition on silicon substrates with nickel as a catalyst particle. The SEM, TEM has been used in order to determine the structure of the films, which show that the diameters of nanotubes are 50~70 nm. characterization has been measured on the CNT-anode setup room temperature and in a vacuum chamber. The Fowler-Nordheim plot shows a good linear fit, indicating that the emission current only comes from the protruded nanotubes. Threshold field strength of this nanotubes film is about 8 V/mm for an emission current of 1 mA, and the most field emission current densities of more than 2 mA/cm2 are measured for 11 V/mm. In addition, the bright light spot can be observed, while emitted electron bombardment fluorescent screen.