Abstract: Herein we present a novel approach to produce Au nanoclusters (NCs) in the pores of mesoporous silica nanoparticles (MSN) by sequential and controlled addition of metal ions and reducing agents. Monodisperse MSNs were prepared by using a sol- gel method. The impregnation technique was followed to confine Au NCs inside the pores of MSN without adding external ligands or stabilizing agents. The synthesized materials were characterized by zeta potential, BET, ICP-OES, UV-vis, transmission electron microscopy (TEM) techniques. TEM images show a uniform distribution of NCs over the entire MSN. The confinement of NCs may enhance their stability and the catalytic performance.