【Objective】 Methanotrophs, using methane as carbon and energy sources for growth, play an important role in keeping balance of global methane in balance and controlling greenhouse effects. The process of bio-oxidation of methane spans over different redox niches. Recent researches demonstrate that methanotrophs. Belonging to the phylum of Proteobacteria have the potential of methane metabolism in anoxic niches of wetland, however so far little has been reported on mechanisms of their energy metabolism. This study was to explore mechanism of the energy metabolism of the Proteobacteria dominated methanotrophs in anoxic niches from three aspects.【Method】Bioelectrochemical techniques were used to explore potential of extracellular electron transfer of the methanotrophs. In exploring for potential electrons of the methanotrophs, the reaction system, when aerobic, was designed to have two potential electron acceptors, i.e. oxgyen and ferrihydrite and when anoxic, only one, i.e. ferrihydrite to study energy metabolism of the methanotrophs in anoxic conditions. Mineralogy analysis of the ferrihydrite in the system was performed to determine reduction dynamics of the mineral and structure of its secondary mineral. And analyses of community composition of the methanotrophs before and after reduction of the ferrihydrite were conduction to determine changes in the community.【Result】Results show that the methanotroph groups were able to transfer directly or indirectly extracellular electrons. Once oxygen was used up, the methanotrophs could keep on their energy metabolism by making use of ferrihydrite as electron acceptor. In the anoxic condition, the methane-oxidizing bacteria could reduce the iron mineral 50 times as fast as the ANME (Anaerobic methanotrophic archaea) anoxic methanotrophic archaea, and the secondary mineral were tentatively found to be vivianite via SEM (Scanning electron microscope), EDS (Energy disperse spectroscopy) and XRD (X-ray diffraction) analysis. Based on the principal component analysis of the methanotroph groups, the microbial community varied in composition relative to mode of energy metabolism. Comparison of the methanotroph groups at the phylum level found that in the hyperoxic systems, γ-Proteobacteria in reduced ferrihydrite increased up to 56% in relative abundance, and Methylococcales became the only one species of methanotroph in phylum, while in the anoxic systems, γ-Proteobacteria decreased down to 6% in relative abundance, but α-Proteobacteria increased up to 31%. 【Conclusion】In the anoxic systems, methanotrophic bacteria (γ-Proteobacteria) and non-methanotrophic bacteria worked together driving iron reduction. This study has revealed the process of energy metabolism of the Proteobacteria dominated methanotroph groups, and developed the theory of methane oxidation driven by NC10 bacteria and ANME archaea in anoxic environment, and hence provide certain theoretic support to future studies on bio-control of methane prodction.