One dimension model of Ca2+ ion transportation during concrete leaching dissolution was developed and the transportation could be numerically simulated. On the basis of some parameters achieved by the experiment of concrete leaching dissolution, the model was solved by FEM(finite element method). The numerical simulation result is accord with experimental phenomenon. The result also indicates the permeability of concrete is a key factor to the performance of concrete leaching dissolution. The concrete leaching dissolution is to be limited even under soft water when the permeability of concrete is a less value.