A B S T R A C TThe biosynthesis of silver nanoparticles by the reduction of aqueous silver metal ions during revelation to both fresh, dry tuber extract and in vitro antioxidant, antibacterial activity of sweet potato were studied. Tuber extract of sweet potato was prepared for the synthesis of silver nanoparticles under different reaction time. The prepared materials were characterized by UV-visible spectroscopy, X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). During incubation period, the intensity of colour increased and its characteristic absorption was recorded at 428 and 439 nm. X-ray diffraction showed that the average particles size 4.77 and 5.6 nm. The FT-IR spectra of the tuber extract and synthesized silver nanoparticles revealed the reducing and capping actions of biomolecules such as amine, peptide, amide, lactone, polyphenol groups in protein linkages and it was found to be involved in the stabilization and biosynthesis of AgNPs. Scanning Electron Microscopy (SEM) showed silver nanoparticles was pure and the sizes were ranging from 1-10 µm. Green synthesized silver nanoparticles exhibited strong antioxidant and effective antibacterial activity against human pathogenic bacteria. Thus, green synthesis seems to be cost effective and alternate to conventional methods of silver nanoparticles synthesis. No synthetic reagent were used in this investigation and thus it is an environmentally safe method with potential for biomedical and agriculture application.