In this paper we report the preparation of carbon nanotubes (CNTs) by ethanol catalytic combustion (ECC) technique. We employed cobalt salt as catalyst precursors, copper plate as substrate and ethanol as carbon source. In order to have a better understanding of the growth mechanisms, we employed cobalt chloride, cobalt nitrite and cobalt sulfate as catalyst precursor to study the influence of catalysts on CNTs growth respectively. Entangled and nonseparated CNTs were aggregated together when the catalyst precursor was cobalt chloride, while straight and uniform CNTs were obtained when the catalyst precursor was cobalt sulfate. In the case of using cobalt nitrite as catalyst precursor, the CNTs tend to form helical and disordered structure. We have examined the morphology and microstructure of the obtained CNTs and discussed the growth mechanism.