Abstract: In order to study the distribution of chloride transport in concrete under dry-wet cycling condition , the compartment model in medical biological mathematics is applied . This model can dynamically calculate the concentration of chloride in the convective region and the diffusion region of concrete under dry-wet cycling condition under different time .In conjunction with experimental data and least square method , parameters in the model can be acquired .And then , the consequence of model can be gained .The form of consequence is not too much complex so that it can be easily applied in practice engineering .The model mentioned in this article provides references to chloride monitoring and concrete durability design for coastal engineering .

Key words: concrete;dry-wet cycle;chloride;compartment model