Zinc oxide (ZnO) microrods were fabricated on graphene/SiO(2)/Si substrate by a simple hydrothermal route. The obtained products were characterized using X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, photoluminescence and UV-visible spectrometry. Microrods exhibits hexagonal wurzite structure. Some ZnO clusters and twinned ZnO structures were found spread on the microrod array layer. The formation mechanism of ZnO microrods is discussed, emphasizing the formation mechanism of isolated clusters and twinned ZnO structures. Furthermore, microrods demonstrated a good photocatalytic performance towards rhodamine B degradation as ascribed to oxygen vacancies and interstitials considered as the photocatalytical active sites.