NOVELTY - A polymer nano-fiber with functional groups is prepared by electro-spinning. The electrospun polymer nano-fiber is contacted with reducing agent, such that epoxy ring on surface of fiber is opened and reduced with reducing agent. The reducing agent modified polymer film is reacted with a metal salt solution in alkali media. The electrospun mat is treated with water, and metal-coated polymer nano-fiber is prepared.    USE - For preparing metal-coated polymer nano-fibers used for nanotubes, catalysts, conductors, solar cells, electrodes for sensors, electrochemical actuators, proton exchange, membranes and electrodes, hydrogen storage membranes, high density packing structure, thin film transistor, reflectors, compact disks and electroconductive applications (all claimed).    ADVANTAGE - The method enables simple and economical production of metal-coated nano-fibers, within a short period of time. The metal-coated organic polymer has excellent conductivity and catalyst properties, and is washed and re-used due to its cross-linked structures.    DETAILED DESCRIPTION - A polymer nano-fiber with functional groups providing the binding ability to reducing the agent is prepared by electro-spinning at ambient conditions. The electrospun polymer nano-fiber is contacted with the reducing agent, such that the epoxy ring on the surface of polymer nano-fiber is opened and reduced with the reducing agent. The reducing agent modified polymer film is reacted with a metal salt solution in alkali media. The electrospun mat is treated with water to open the electro rings in the structure, and the chains are cross-linked to provide integrity. Thus, the metal-coated polymer nano-fiber is prepared. INDEPENDENT CLAIMS are included for the following:    (1) metal-coated polymer nano-fibers;    (2) use of metal coated polymer nano-fiber;    (3) catalyst; and    (4) conductor.    DESCRIPTION OF DRAWING(S) - The graph shows the 1H nuclear magnetic resonance (NMR) spectrum of poly(acrylonitrile-co-glycidyl methacrylate) (PGMA).