An  Contemporary affirm of explore on the green synthesis of metal oxide nanoparticles and their improvement over chemical synthesis routine. In this method, non-hazardous safe reagents that are eco-friendly and biosafe are used.  Consequently, an attempt is to prepare the Nickel Oxide (NiO) nanoparticles via Chemical and Green synthesis method.  To Synthesize the pure NiO and GS-NiO nanoparticle with reducing agent of  Plectranthus Amboinicus leaf extract used and calcinated at 400^oC  in a controlled manner.  To study the phase nature, functional groups and Optical energy band gap of the synthesized pure NiO and GS-NiO nano particles by using XRD, FT-IR and DRS-UV.

Keywords: NiO, Plectranthus Amboinicus leaf, XRD, FTIR, UV-DRS, SEM-EDAX.