This paper describes the governing equations of moisture, heat, and chloride ion flows through concrete within the framework of a distributed parameter model. The coupling terms and the nonlinearity of the problems are taken into account and a numerical procedure based on the finite element method is developed to solve the set of equations. This study examined chloride diffusion even in partially saturated concrete by considering the variability of ion diffusion coefficients with concrete parameters. Chloride intrusion in various environmental conditions was investigated and the effect of moisture flux in transporting dissolved ions through the porous media is considered. Comparisons with experimental tests are also carried out to show the reliability and the effectiveness of the proposed numerical model.