Abstract: Electron sources and CNTs（carbon nano tubes） negative materials are two of the most promising applications of CNTs in the future. The synthesis of CNTs at low temperature has received a great deal of attention and becomes a challenging issue. Carbon nanotube films were synthesized on Ni substrate by microwave plasma chemical vapor deposition at low temperature. Because of the strong etching ability of hydrogen plasma, high pure carbon nanotubes can be produced at temperature range from 470 ℃ to 510 ℃. The temperature of Ni substrate, which was determined mainly by the plasma intensity, affects the growth of CNTs. At a substrate of 470 ℃, the CNTs are curly, whereas the CNTs were straight at temperature of 510 ℃. The grown rate of CNTs increased with the increase of plasma intensity.