One-dimensional structured (1D) nanofiber materials have attracted great interest over the past decade because they can potentially address many advanced applications involving dimensionality and size-confined quantum phenomena. They are expected to play a crucial role as interconnects and functional units in fabrication of lab-in-chip, electronics, electrochemical, optoelectronic and electromechanical devices with a nanoscale dimension. This book discusses the recent advances in synthesis and development of nanofiber materials and the potential applications of these 1D nanostructured materials.