Bamboo-like nitrogen-doped carbon(CNx)nanotubes were synthesized by chemical vapor deposition (CVD)at a high reaction temperature of 600-900 ℃.The butylamine and Fe/SBA-15 molecular sieve have been used as precursor and catalyst,respectively.Transmission electron microscopy(TEM)and high resolution transmission electron microscopy(HRTEM)observations show that the outer diameter and wall thickness as well as the inner diameter were increased with increasing reaction temperature in a temperature range of 600-800 ℃.A synergism mechanism of the growth through bulk diffusion and the competitive growth through surface diffusion functions during the synthesis of CNx nanotubes was proposed.