The present study reports the extracellular biosynthesis of silver nanoparticles by alkalophilic Streptomyces species and its characterization. The biological synthesis would be beneficial because the development of clean, non-toxic and eco-friendly procedures by using microorganisms and plants for the synthesis of nanoparticles. Biosynthesized silver nanoparticles were confirmed by UV – visible spectroscopy, the spectra showed a maximum absorption peak at 410 nm and the FT-IR analysis, provides evidence for the presence of proteins as capping agent which helps in increasing the stability of the synthesized silver nanoparticles. Further analysis by EDX revealed that about 56.40% of silver present in the sample, which is represented by the strong silver signals. The XRD and TEM confirmed the silver nanoparticles were spherical in shape and size in the range of 20-40 nm. The potential actinobacterial strain was identified by phenotypic, cultural and genetic characteristics.