Both ZnO nanocomb and nanotetrapod structures have been synthesized via a simple chemical vapor deposition process in a horizontal tube furnace. The morphology of the products is affected by the distance between the source material and the deposition substrate. The formation of nanocombs has been attributed to the self-catalysis effect of polar surface. The octahedral multiple-twin model is responsible for the formation of tetrapods and tripod-like arms at the end of nanowires. The evolutive process of them has been given out in detail and the results provided valuable models in understanding crystal growth mechanisms in nanometer building-blocks and to further grow net nanostructures. And their photoluminescence properties also have been discussed.