The synthesis of silver nanoparticles is an active area of academic and industrial application research in the field of nanotechnology. A variety of chemical and physical procedures could be used for the synthesis of silver nanoparticles. There is an essential need to develop environmentally benign procedures for the synthesis of silver nanoparticles. One promising approach to achieve this would be by a green synthesis method. In the present study green synthesis of silver nano particles were biosynthesized from marine alga Colpomenia peregrina and investigating characteristics using UV-Vis spectroscopy, X-Ray diffraction studies (XRD), Fourier-Transform Infra Red (FT-IR), Thermo Gravimetric Analysis (TGA), and Transmission Electron Micrograph (TEM).