The micro-nano multi-scale ZnO structure was synthesized by the vapor phase transport process onto Si (100) substrate. A typical scanning electron microscope (SEM) image of the sample clearly showed the surface has the complex structure of hexagonal micro and nano- rods. Photoluminescence (PL) spectra at room temperature showed an intense near-band-gap ultraviolet (UV) emission peak but no deep level emission related to impurities or defects, indicating that the sample has good optical quality. The temperature (83—307K) dependence of the PL spectra showed that the room-temperature UV emission resulted from two optical transitions, one related to the ZnO free exciton and the other related to the free-to-bound (FB) transition of the free cawier with the binding energy of about 124.6meV.