Abstract: The selectivity coefficient of the system, L-Lysine/ammonium type sulfonic cation-exchange resin, was determined and its kinetic studies showed that it is particle-diffusion controlled. A method based on the Vermeuten method, was proposed for the calculation of the fixed-bed ion-exchange column under the constant-pattern mode. The method was proved to be in good agreement with the experimental results and could be used for the design of the L-Lysine ion-exchange column.