Diffusivities and equilibrium absorption of sodium chloride and glycerol in cation exchange resin Dowex-50 were determined by making a two-constant fit of experimental data to a diffusion model. The variables studied were: resin cross linkage—2% to 12% divinylbenzene, temperature—25° to 80°C, concentrations in the equilibrating solution, resin particle size, flow rate of the eluting distilled water. Diffusivities increase with decrease in cross linkage and with increase in temperature. The ratio of the diffusivities of sodium chloride or glycerol in the resin to that in water is between 0.2 and 0.35 for 2% DVB and between 0.025 and 0.1 for 12% DVB. Diffusivities were found to be independent of the third, fourth, and fifth variables. The amounts of solutes absorbed at equilibrium also increased with a decrease in cross linkage and an increase in temperature.