Pyramid shaped pyrolysis flame is a new method for carbon nanotubes (CNTs) synthesis. Oxy-acetylene flame was used as the source of heat, CO as the source of carbon, iron pentacarbonyl (Fe(CO)5) as the source of catalyst precursor. Field emission scanning electron microscope(FE-SEM), High resolution transmission electron microscopy (HR-TEM) and Raman spectra were used to illustrate the results of experimental. In this experimental, coating substrate is not a special process, but a part of sampling. In the first 60s of sampling time, there were not CNTs synthesis, only the phase that substrate coats particles and temperature rise, so in this phase, catalyst particles formed. 304 stainless steel plate, monocrystalline silicon chip, and brass plate were used as substrates to synthesize CNTs. 304 stainless steel plate could gain straight, long, and uniform CNTs, monocrystalline silicon chip gain curly and short CNTS, while brass gain nothing but particles. Although single-walled carbon nanotubes (SWNTs) were not observed by SEM and TEM, it was successfully done by Raman spectra, in spite of the yield was small.