Abstract: The clone library and quantitative PCR technologies were used to investigate the characteristics of spatial-temporal distribution and community structure of “Candidatus Methylomirabilis oxyfera” (M. oxyfera) in the sediments of the Hun River, which plays an important role in the process of nitrite-dependent anaerobic methane-oxidizing. The spatial diversity analysis showed that there was no significant regional difference in the diversity of 16S rRNA in the sediments of the Hun River from the upstream to downstream during the wet period. The diversity of the pmoA gene had obvious regional differences; the maximum OTU number was 5 at the upstream sampling point, and the minimum was 1 at the downstream sampling point. The seasonal diversity analysis showed that both the diversity of 16S rRNA and pmoA showed seasonal differences at sampling point A. The Shannon-Wiener diversity indices of 16S rRNA and pmoA genes in the normal season were 1.48 and 2.19 respectively, which were highest during all of the three water seasons, while the minimum values were 0.83 and 1.26 in the dry season, respectively. The abundance analysis showed that the 16S rRNA gene copy number of all sampling points was highest during the normal season (2.42×10⁶-1.74×10⁷ copies/g), ranged from 2.87×10⁴ to 4.19×10⁶ copies/g during the dry season, and were lowest during the wet season (1.29×10³-2.04×10⁴ copies/g). Thus, there are some seasonal differences of the abundance of M. oxyfera-like bacteria in the sediments of the Hun River.