Abstract: Carbon nanotubes (CNTs) were grown on carbon fiber cloth surface in-situ via catalytic chemical vapor deposition method. The evolution of morphology and structure of CNTs grown at different positions along gas flow direction were studied using scanning electron microscopy, Raman spectra and transmission electron microscopy. The results show that aligned growth of CNTs could be achieved at different positions along gas flow direction. Although CNTs grown at different positions exhibited the same structure and quality, the lengths of CNTs were different. The length of CNTs grown near the gas outlet were almost twice of that of CNTs grown near the gas inlet.