Poly (ether-block-amide) resin-1657 (Pebax-1657)/AgBF4/Al(NO3)(3) electrolyte membranes were prepared for olefin/paraffin separation. To solve the low permeance of facilitated transport membranes consisting of polymer/AgBF4/Al(NO3)(3), Pebax-1657 to have 40% amide groups and 60% ether groups was selected as polymer matrix for high permeance. As a result, the selectivity (propylene/propane) and mixed gas permeance of Pebax-1657/AgBF4/Al(NO3)(3) electrolyte membranes were observed as 8.8 and 22.5 GPU, respectively. The enhanced permeance compared to the performance reported in previous membranes consisting of polymer/AgBF4/Al(NO3)(3) was attributable to the flexible segments of ether groups in Pebax-1657. Furthermore, the prepared Pebax-1657/AgBF4/Al(NO3)(3) electrolyte membranes showed the long-term stability by stabilizing effect of Al(NO3)(3) on silver ions as olefin carriers.