Abstract: A novel polycation electrolyte was synthesized by quaternizing polyvinyl alcohol(PVA) with (3-chloro-2-hydroxypropyl)-trimethylammonium chloride (CHTMAC) and using KOH as catalyst.The product was named as quaternized PVA(QAPVA).The factors affecting the quaternization reaction were investigated and optimized.The degree of substitutions of QAPVA increased from 1.0% to 6.7%.QAPVA exhibited higher glass transition temperature.The conductivity of QAPVA aqueous solution showed direct proportional relationship with QAPVA concentration.PVA and QAPVA were further prepared into the dense membranes and observed membrane surface morphology.It was found that the surface of PVA membrane was flat, whereas the surface of QAPVA membrane took on many spherical tubes.Furthermore, the QAPVA membrane showed permeation flux of 250 g•m^-2•h^-1 and separation factor of 1540 when dealing with water/ethanol system ［containing 95.4%（mass）ethanol］ at 75℃.QAPVA was further compounded with phosphatized anionic PVA(PAPVA)to prepare a new polyelectrolyte complex and thereby utilize the new complex to separate water/ethanol［containing 95.4%（mass）ethanol］.The results indicated that the complex had permeation flux of 380 g•m^-2•h^-1 and separation factor of 2250 for water/ethanol system.