The membranes containing facilitated transport groups for Carbon dioxide had been prepared by immobilizing PAMAM ( Polyamidoamine) (Generations 0,1,2,3,4) dendrimer into the polymeric membranes. The dendrimer incorporated membranes were prepared by the phase inversion method. The permeation abilities of the membranes for pure CO 2 and binary mixture of CO 2 /N 2 were calculated. The effects of feed gas pressure on the permeability of the membranes were studied. The results of the permeation experiments showed that PAMAM dendrimer (Generation 4) composite membrane possessed a better CO 2 permeability and selectivity over N 2 than the any other membranes composite with other generations of dendrimer (Generations 0,1,2,3).