Single-crystalline ZnSe/Ge bi-axial heterostructural nanowires were grown via a simple one-step thermal evaporation of mixed ZnSe and Ge powders. The heterostructure nanowires have uniform diameter of 200 nm and their length ranges are from several tens to several hundreds of micrometers. Both the zinc-blende ZnSe and diamond-like cubic Ge sub-nanowires in the heterostructures are single crystalline, and grow along the [1 1 1] direction. The sub-nanowires of ZnSe and Ge, with ideal interfaces along the growth orientation, have diameters of 120 and 80 nm, respectively. The experimental evidence suggests that the bi-axial nanowires are formed via a co-growth mechanism. The vibrating property of the nano-wire was investigated by Raman spectroscopy at room-temperature. Crown Copyright (C) 2010 Published by Elsevier B. V. All rights reserved.