In order to develop a better understanding of the relationship between 90-day salt ponding test and accelerated chloride migration test (ACMT; the electrochemical technique is applied to accelerate chloride ion migration) to assess the resistance of concrete to chloride penetration. The plain cement concrete and concrete containing different type of mineral admixtures (fly ash and slag) with w/b ratios of 0.35, 0.45, 0.55 and 0.65 were used. In this study, the total chloride content and penetration depth of concretes were measured after the ponding test, and the Fick's second law of diffusion was fitted to the data from experiment to determine the diffusion coefficient. The non-steady-state diffusion coefficient was calculated from the modified second Fick's law by using ACMT in the previous study. The chloride diffusion coefficient from ponding test and the non-steady-state diffusion coefficient from ACMT were compared. The results for all mixtures show that the chloride diffusion coefficient from ponding test and the non-steady-state diffusion coefficient from ACMT are linearly correlated. (C) 2004 Elsevier B.V. All rights reserved.