In this research work has been synthesized and characterized by chemical route monometallic and bimetallic nanoparticles Core / Shell (Au / Ag), using two-step method involving the preparation of a solution of nuclei formed by gold nanospheres and its union with the armor formed by silver nanospheres; to this, the final size of the nanostructure, intimately dependent kernel size for that matter studied and experimentally examined the influence of parameter variation in the synthesis process._x000D_ It basically studied the influence of synthesis parameters on the gold nucleus, then it choose the best conditions and make the coating and produce silver bimetallic nanostructures. Variations were such as: Method of synthesis of the nanosphere, temperature stabilizing cetyltrimethylammonium bromide (CTAB) 65, 75, 85 and 95 °C, precursor Origin of chloroauric acid (HAuCl4) Stabilizer Type hom...