Electrochemical membrane systems have drawn to significant attentions due to their unique permselectivity and engineering applications such as electrodialysis and electrochemical battery, etc. In the membrane systems, dielectric spacers should be installed between cation- and anion-selective membranes in order to prevent the contact of the each selective membrane surface. In usual, the conventional dielectric spacers were used as a mixing promoters which were developed in the absence of considering the electrohydrodynamic interaction with concentration polarization layer. In this work, we investigated the electrohydrodynamic effects of charged dielectric spacers in the membrane system by an boundary layer model and actual micro/nanofluidic experiments. Through a rigorous analysis, we found three regimes of spacer-integrated electrochemical membrane system: (i) surface conduction dominant regime, (ii) electroosmotic flow dominant regime and (iii) non-conducting limit regime. These fundamental findings would provide effective means for micro/nanofluidic engineering applications as well as electrochemical desalination devices.