Abstract: Acetylene cracked under normal pressure at 700-800℃ with active nanoscale cobalt particles as catalyst and carbon nanotubes were prepared on a large scale. The final product rate was above 50wt% after 10min growth, and also defects were almost nonexistent. The lengthes of the carbon nanotubes ranged from 5 to 30μm. Non-well distributed carbon on catalyst surface accelerated the nucleating process. The growing time limitation was about 15min and then growing process became slow.

Key words: carbon nanotubes, CVD, normal pressure, sol-gel