Abstract: The various embodiments herein provide method of producing a rod-shape and branched metal nano-structures with polyol compounds as a reducing agent. The metal nano-structures are produced in a closed chamber of microwave system with variable irradiation power at a designed temperature. The metal nano-structures produced exhibits localized plasmon-polariton resonance, exhibit spectral resonance positions at microwave or radio frequencies and exhibit multiple spectral resonance peak at microwave or radio frequencies. The metal nano-structures produced are suitable as a coating composition material, a coating, a film, a wiring material, an electrode material, a catalyst, a colorant, a cosmetic, a near-infrared absorber, an anti-counterfeit ink and an electromagnetic shielding material, a surface enhanced fluorescent sensor, a biomarker and a nano-waveguide.