The vertically aligned uniformed carbon nanotubes (CNTs) oil 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 mum. High-resolution TEM analysis reveals that the CNTs have the uniformed multi-walls, the bamboo structure, and the sharp closed tip. 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.