Nanocombs with a disc cap structure of ZnO have been synthesized on si substrates by using pure Zinc powders as the source materials based on a vapour-phase transport process.The morphology and the microstructure are investigated by a scanning electron microscopy and x-ray diffraction.Based on the transmission electron microscopy and selected area electron diffraction analysis,the growth directions of three representative parts,nanoribbon stem,nanorod branch and nanodisc cap of the nanocomb are revealed.The growth mechanism of the disc-capped nanocombs is discussed based on the self-catalyzed vapour-liquid-solid process.