In my work, we synthesis ZnO nanoparticles are synthesised by the precursor Zn (OAC)2 to study its behavior at nanoscale. Green synthesis method (Biological method) is used for the preparation of ZnO nanoparticles. Green synthesis method is based on the natural world, natural chemicals are used and solvents for green methodology are received from natural resources. In present world nanomaterials tested by various characterization techniques. Information about the interplanar distance, strain, crystalline size and phase of the nanomaterial validate by the trace of XRD pattern. By Scanning electron microscope (SEM) is used to Nano atoms probability at surface and the size of the nanoparticle is determined. By Fourier transform infrared (FTIR) spectroscopy is used to find out different functional groups of ZnO at particular wavenumber. Absorption peak and optical band gap (3.79 eV) of the sample is determined by UV visible spectroscopy. In this study Photocatalytic degradation of MB dye is also performed in the influence of the UV light and sun light.