In this study, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS) was introduced into polymer gas separation membrane. The composite membrane consisted of poly(2-[3-(2H-benzotriazol –2-yl)-4-hydroxyphenyl] ethyl methacrylate)-poly(oxyethylene methacryalate) (PBEMPOEM) comb copolymer matrix and PEDOT-PSS filler. PEDOT-PSS has strong ionic bonding interaction between PEDOT and PSS, and sulfonic acid groups in PSS interact with water molecules with hydrogen-bond. Because of these specific properties, the incorporation of PEDOT-PSS could form CO2 pathway for gas transport through the membrane. PEDOT-PSS chains were homogeneously dispersed in the PBEM-POEM matrix as a network. The best performance of prepared PEDOT-PSS/PBEM-POEM composite membranes was CO2 permeability of 59.6 Barrer with a CO2/N2 selectivity of 77.4, being close to the 2008 Robeson upper boundlines.