Two kinds of modified styrene-butadiene-styrene triblock copolymer (SBS) were used as polymeric axial ligands in this work, one was modified by radiation-induced graft copolymerization to obtain styrene-butadiene-styrene-g-vinylpyridine (SBS-g-VP), and the other was modified by epoxidation to obtain epoxidized styrene-butadiene-styrene block copolymer (ESBS). Then the complex formation of modified SBS (SBS-g-VP or ESBS) with (N,N’-disalicylideneethylenediamine)cobalt(II) (CoS) in chloroform solution was studied. Facilitated transport of molecular oxygen in modified SBS membranes containing CoS as fixed carrier of oxygen, and oxygen permeability in modified SBS membranes and oxygen binding ability to CoS were studied. The facilitation was enhanced in the polymeric complexed membranes (SBS-g-VP-CoS and ESBS-CoS), and the different facilitated results of SBS-g-VP-CoS and ESBS-CoS are discussed.