Poly(vinylidenefluoride-co-chlorotrifluoroethylene) P(VDF-co-CTFE) polymer was attached to methacrylic acid(MAA) in the presence of 1,8-diazabicyclo[5,4,0]undec-7-ene(DBU) catalyst to prepare P(VDF-co-CTFE)-MAA copolymer.The modified P(VDF-co-CTFE)-MAA was polymerized with 2-sulfoethyl methacrylate (SEMA) monomer in the presence of4’,4’-azobis(4-cyanovaleric acid(ACVA) initiator by free radical polymerization to form the proton conducting membrane.The ratio of the SEMA was increased in the membrane to increase the presence of the acidic group. The maximum IECvalue that was observed at 50% SEMA was around 0.82 meq/g, which is consistentwith the water uptake value. The highestproton conductivity achieved by P(VDF-co-CTFE)-MAA/SEMA membrane with 50% SEMA was approximately 0.041 S/cm.This indicates that the available ionic group for the proton conduction increases with the increase in the SEMA in themembrane.