Deoxidizer Na2S/AC was modified with transition metal ions (Co2+, Ni2+, Fe3+, and Cu2+) by co-impregnation and step-by-step impregnation methods. Those deoxidizers were characterized and tested for the removal of O-2 from low concentration coal bed methane. Results showed that the effective deoxidizing amount of deoxidizers (Q(O2)) and conversion rate of Na2S (C-Na2S) of the deoxidizers are in the following order: Co-Na2S/AC > Ni-Na2S/AC > Fe-Na2S/AC > Na2S/AC > CuNa2S/AC. As compared to that of the deoxidizer Na2S/AC, the content of reactive oxygen species (O -) pound of the modified deoxidizers was enhanced with the doping of transition metal ions (Co2+, Ni2+, Fe3+, and Cu2+). The more content of O - pound on the deoxidizer was, the higher deoxidizing activity there was when the dispersion of Na2S and metal ions of deoxidizers was higher. The deoxidizer Co-Na2S/AC had the largest content of O - pound and higher dispersion of Na2S and Co2+, and this made it the largest Q(O2), (54.88 mL/g) and C-Na2s (75.50%) at 200 degrees C. However, although the content of O - pound of the deoxidizer Cu-Na2S/AC was higher than that of the deoxidizer Na2S/AC, the deoxidizer Cu-Na2S/AC had the smallest Q(O2) and C-Na2s due to the more severe agglomeration of S-6 and the larger crystal of Cu(OH)(2) on this deoxidizer. The deoxidizer Co-Na2S/AC prepared by a step-bystep impregnation method had higher content of O - pound, higher dispersion of active component Na2S and assistant Co2+; this made it the higher deoxidizing activity compared with the deoxidizer Co-Na2S/AC(c) prepared by a co-impregnation method.