In this paper, a kinetic model for the radiation-induced production of the intrinsic point defect E′ center is proposed. The relation of E′ center concentration changing with dose is obtained. The results show that the production of E′ center includes two processes, i.e. the creation of new defects and the activation of preexisting defects. The stained bonds (or oxygen replacement) in silica networks lead to the creation of new defects, whose concentration increases linearly with the dose. The preexisting defects produce the activation, which tends to saturation. The theoretical result is in good agreement with the experiment.