Biogenic silver nanoparticles have been green-synthesized using the aqueous extract of shallot (Allium ascalonicum) as the reducing and stabilizer agents. The UV-vis spectrum of the biosynthesized silver nanoparticles showed a characteristic surface plasmon resonance peak at 414 nm, confirming the presence of silver nanoparticles. Also, the Central Composite Design under Response Surface Methodology had been applied to optimize the effects of independent factors such as the stirring time, extract volume, silver nitrate concentration, and the stirring rate on the response value that is the maximum absorbance of biosynthesized silver nanoparticles. The results showed that all variables contributed significantly to the biosynthesis of AgNPs. The R-square value of 0.9873 of the obtained model indicated a good correlation between the predicted and the observed values. Under the optimized conditions, the biosynthesized silver nanoparticles had their crystallite nature and the mean sizes of the biosynthesized AgNPs were 17 nm based on Scherrer equation. While, DLS measured the particles sizes of the AgNPs were 49.5 nm with the polydispersity index of 0.690. The SEM image revealed that the sharp of AgNPs was in the spherical forms. The chemical nature of the synthesized AgNPs was also characterized by using FT-IR.