A poly(vinyl chloride) (PVC)/glycidyl methacrylate (GMA)-divinyl benzene (DVB)-based membrane was prepared via monomer sorption, and then pyridium or its derivates (that is, 4-ethyl pyridium, 4-tetrabutyl pyridium) were introduced into the PVC/poly(GMA-DVB) base membrane. The effects of pyridinium anion-exchangeable sites on the water splitting and the electrochemical properties of the membrane were investigated. The electrochemical properties and the water splitting on the anion-exchange membranes were compared with selected commercial membranes containing quaternary ammonium groups. The pyridium membranes showed good electrochemical properties, comparable to those of the commercial membranes, with electrical resistances of less than 3.0 X 10(-4) Omega(.)m(2) in 0.5 mol dm(-3) NaCl and high ionic permselectivities (the transport number of Cl- ions being 0.96). Moreover, water splitting indicated by the proton transport numbers of the membranes containing pyridinium or its derivates, were about two or three orders of magnitude lower than those of the commercial membranes (such as AM-1) at the same current density because the resonance effect in the quaternary pyridinium groups contributed to their molecular stability.