Si E′ centers were induced in high-purity silica glass after infrared fs(femtosecond) laser exposure. The concentration of the color centers increased linearly with the laser intensity and the number of scan time below the optical breakdown threshold. From the results of absorption, ESR and photo-luminescence spectra measurements before and after fs laser irradiation, the processes of Si E′ center formation were proposed. The self-trapped excitons are ascribed to the main reason of color centers formation.