Chloride penetration into concrete is the main cause of the corrosion of steel in concrete structures exposed to chloride-rich environments. As a preventive or remedial method, surface treatments on concrete have been increasingly applied to both new and existing concrete structures to combat this problem. So far, knowledge of how a surface treatment reduces chloride diffusion is limited and the relationship between chloride diffusion resistance and surface treatment parameters, such as thickness, porosity and diffusion coefficient, has not been quantitatively identified. In this paper, chloride ion penetration modeling is performed to predict the service life of the surface treated concrete.