[en] The vertically aligned uniformed carbon nanotubes (CNTs) on a large area of Ni deposited Si substrates were grown by thermal chemical vapor deposition using C₂H₂ gas. The diameter of CNTs is as small as about 60 nm and the length is about 50 μm. High-resolution TEM analysis reveals that the CNTs have multi-walls with good crystallinity and there are some defects on the wall surface. The base growth model is suitable to bamboo-shaped CNTs using thermal chemical vapor deposition