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Proton/cadmium(II) ion exchange kinetics on sulfonated polystyrene resins of type gel, macroporous, and hypercross-linked were investigated using a potentiometric method in conditions favoring a particle diffusioncontrolled mechanism. The data were modeled with different quasi-homogeneous resin phase kinetic models and with the Ruckenstein et al. bidisperse pore model. The interdiffusion and self-diffusion coefficients were obtained and reported. The diffusion coefficients on resins with different texture slightly decrease in the series hypercross-linked g gel > macroporous resins. The evaluated ratio between the sulfonic groups grafted in micro-and macropores was 1 / 60 for the macroporous resin and 1 / 100 for the hypercross-linked one. The evaluated Cd 2+ self-diffusion coefficients were 8.4 × 10 -12 , 6.4 × 10 -12 , and 9.1 × 10 -12 m 2 s -1 , while the evaluated H + self-diffusion coefficients were 1.7 × 10 -10 , 1.4 × 10 -10 , and 4.1 × 10 -10 m 2 s -1 on gel, macroporous, and hypercross-linked resins, respectively.