One-dimension Zinc oxide (ZnO) nanorods were successfully synthesized by calcining the precursors, which were produced by a chemical precipitation method. Scanning electron microscopy (SEM)and transmission electron microscopy (TEM) results showed that the diameters of the nanorods were about 40-50 nm and the lengths up toìm scale. High-resolution transmission electronmicroscopy confirmed that the quadrangular ZnO nanorods had a wurtize structures and growalong the (0001) direction, and whichwas explained by the Âlowest-energyÂ theory. the product transformed fromlong rods to rods composited of stacked nanoplates along with the increase in citrate concentration. The calcining temperature and citrate concentration were the key parameter for the morphology of the ZnO products.