Synthesis and stabilization of silver nanoparticles in different reaction conditions have been carried out with gum arabic with an average molecular weight of 200 kDa and 40000 of polyethylene glycol, as well as in  200 kDa chitosan (Cht) condition in the presence of small concentration of  NaBH₄ and HCOOH  aqueous solutions at 293–353 K temperature. The sizes of obtained silver nanoparticles were investiqated by X-ray phase analysis. It was determined that the size of silver nanoparticles stabilized in polyethylene glycol and gum arabic based co-polymers conditions range between 7–9 nm, while the sizes of formed silver nanoparticles range between 8–11 nm when using Cht being natural polysaccharide as the stabilizer.