To investigate the influence of initial curing conditions and exposure environments on chloride ions?migration in concrete, the specimens that were cured in different conditions and placed in several marine environments were monitored in the accelerated chloride migration test. The effective chloride diffusion coefficients (De) were calculated from the steady-state on the basis conditions and the wet-dry interval of extal environments have coupling influence on effective diffusion coefficient of chloride ion significantly. De reflected the density and pore connectivity of concrete. The co-effects of the initial curing condition and following exposure environment should be taken into account in durability design for concrete structure located in marine environment.