The transport of cobalt ion in a continuous electrodeionization (CEDI) system was investigated in terms of electrochemical proper-ties of ion exchange textile. The porous plug model and an extended Nernst-Plank equation were applied to describe the transport of Co2+ through an ion exchange textile. The transport characteristics of Co2+ during CEDI operation suggested the transport mechanism was due mainly to the increased current induced by the high conductivity in the ion exchange textile, not accelerated ionic mobility. This study suggested the important parameter for the high performance of the CEDI system is the conductivity of the ion exchange media.