In the present work, we investigate the photoluminescence (PL) and structural properties of Si nanoparticles embedded in SiO2 matrix. Si-rich silicon oxide (SRSO) films with Si concentration of 39% were synthesized by reactive RF magnetron sputtering. Annealing was performed at temperatures between 600°C and 1100°C in N2 ambient for 2h to precipitate Si nanoparticles from oxide matrix. Near infrared photoluminescence around 750nm can be clearly observed even in the as-deposited films, which indicates the existence of Si nanoparticles in films. The structural properties were analyzed by infrared absorption and Raman spectra. It is found that the structural properties strongly affect the PL properties of Si nanoparticles embedded in SiO2 matrix.