In this paper, we summarize our recent results of study on how to engineer the embedded metal nanoparticles in silica by ion implantation and ion irradiation technologies, including controlling the size, distribution and morphology of nanoparticles. The optical properties of the tailored nanoparticle composites are studied. Thermal annealing, electron beam irradiation, and chemical erosion are used to study the stability of these embedded nanoparticles by ex situ or in situ transmission electron microscopy observation.