Two ZnO nanostructures with multisegment structure have been synthesized by a chemical vapor deposition(CVD) method on a silicon substrate. The top size of the nanostructures can reduce to 10−30 nm, which isbeneficial to field emission applications. Scanning and transmission electron microscope methods are appliedto analyze the morphology and microstructure of the nanostructures. Cathodoluminescence study shows thatthe ZnO nanostructures have core−shell luminescent structure that will affect significantly the mechanicaland electrical properties of the ZnO nanostructures.