Controlled doping appropriate elements into semiconductor nanostructures is of vital importance to develop novel materials and functional devices. Herein, we present three methods to synthesize Cu-doped ZnO nanostructures using a simple vapor phase transport process and adopting CuCl2, CuO or Cu as doping precursors. The corresponding morphology, structure, and chemical composition were investigated using field emission scanning electron microscope, transmission electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy. We show that these three methods produce nanostructures with different morphologies and doping levels. This work paves the way for investigating the physical properties of Cu-doped ZnO nanostructures and furthermore facilitates the synthesis of other transition-metal-doped nanomaterials.