The chloride diffusion coefficients of mortar specimen coated with different kinds of polymers were determined with normal steady state diffusion test and compared with the results obtained from the accelerated steady state diffusion test. It is found that the time needed to get the results from steady state method is about 1 year for normal diffusion test and about 2 weeks for the accelerated diffusion test. It shows that the chloride diffusion coefficients of the coatings has the similar order in normal diffusion test and accelerated test. This indicates that the accelerated test is a good method for the evaluation of the chloride diffusivity of polymer coatings.