In this research, OMMT/PVDF-based cationic exchange membranes were prepared by two-step chemically induced grafting method. The various preparation conditions, such as alkaline treatment, initiation, and grafting conditions, and the relationship between the preparation conditions and the cationic exchange membrane performance, such as area resistance and cationic permselectivity, were investigated. The chemical and crystal changes on the membrane surface were characterized by Fourier transform infrared spectroscopy (FTIR), energy dispersive spectrum (EDS), and X-ray diffraction (XRD), respectively. Surface morphological changes were also characterized by scanning electron microscopy (SEM). The results reveal that the OMMT/PVDF-based cationic exchange membrane was successfully prepared by this method. The OMMT/PVDF-based cationic exchange membrane doped 8.5% OMMT prepared using optimum preparation parameters showed excellent basic properties. The area resistance was measured as low as 1.8 X cm 2 , while the cationic permselectivity was as high as 93.4%.