The kinetics and mechanism of diffusion of Zn2+, Sr2+, Co2+ and Eu3+ in the H+-form of cerium(IV) antimonate (CeSb) have been studied as a function of particle sizes, reaction temperatures and solution concentrations of the exchanging ions. The exchange rate was controlled by particle diffusion mechanism as a limited batch technique. The physical thermodynamic parameters such as, activation energies and entropies of activation have been evaluated. The mobility of these ions inside the particles of the exchanger decrease in the order: Zn2+ > Sr2+ > Co2+ > Eu3+