Abstract: Uniform ZnO comb-like nanostructures were fabricated successfully with pure zinc powdere-vaporation without catalyst at 600-650 ℃. Scanning electron microscopy （SEM） and high-resolution transmission electron microscopy （HRTEM） observations show that such ZnO nanostructures have two main types in morphology, and both of them are single crystalline. Investigations through HRTEM and XRD reveal that the growth of the synthesized ZnO nanostructures is controlled by vapor-solid mechanism. Room temperature photoluminescence spectrum of the nanocombs shows a UV emission at about 385nm and a broad green emission at 495 nm.