The simulated moving bed (SMB) unit in a chromatographic separation of enantiomers has been modeled and simulated by a computational program. The mathematical model of the unit considers the plug flow model with axial dispersion for the fluid phase and the linear driving force approximation for the intraparticle mass transfer rate. The model assumes the switching of the inlet and outlet streams of the unit for each time interval, and then, allows accompanying the evolution of the internal profiles of enantiomer concentration for the transient operation of the SMB. The mathematical equations with the respective boundary and initial conditions are numerically solved by finite volume method. The influence of bed configuration on the SMB performance has been studied using a computational program. However the purity and recovery of some species are slightly affected by configuration.