Silver nanoparticles (AgNPs) were successfully synthesized from aqueous silk fibroin solution by using UV-irradiation technique. Here the SF solution acts as stabilizer, the effect UV-irradiation time influence the particle size and shape of the AgNPs. The UV-Visible studies evidence the strong surface plasmon resonance (SPR) band at 428 nm, which confirm the reduction of Ag+ to Ag0 in the aqueous SF solution. Transmission electron microscope (TEM) images investigate that the AgNPs are well dispersed in aqueous SF solution, increasing the irradiation time the large number of particles agglomerates of grains with narrow size distribution. The synthesized AgNPs structurally characterized by X-ray diffraction technique. The XRD pattern the peaks are good agreement with the synthesized AgNPs are face centered cubic structure (FCC) with a lattice constant of a = 0.485. The dynamic light scattering (DLS) investigates the particle size distribution and average size of the synthesized AgNPs. The size control and UV irradiation time of AgNPs can affect the significant antibacterial activity against four bacterial stains, i.e. Staphylococcus aureus, Bacillus subtilis (Gram positive) and Escherichia coli, salmonella typhi (Gram negative).