Ammonia-oxidation, performed by both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), is the first and rate-limiting step for soil nitrification process. In the process of grazing, the animal feeding, excretion and trampling will affect the ammonia-oxidizing microorganism communities, while it is unclear whether the different grazing forms will affect the community structure and diversity of ammonia-oxidizingmicroorganism in wetlands. We investigated the diversity and community structure of the AOA and AOB with different grazing forms in peat swamp soils by Illumina Miseq high-throughput sequencing technology. The results showed that yak grazing significantly increased the bulk density, reduced soil pH, NH₄⁺-N, TN, TOC and NO₃^--N content. The stocking of Tibetan spiced pig significantly increased soil NO₃^--N content and potential nitrification rate (PNR).Yak grazing significantly reduced the richness of AOA and the α diversity of AOB. The stocking of Tibetan pigs reduced the α diversity of AOA and the richness of AOB. The grazing significantly reduced the relative abundance of Crenarchaeota. The α diversity of AOA was significantly negative correlated with soil NO₃^--N content and PNR. The α diversity of AOB was significantly positive correlated with pH, TOC, TN and NH₄⁺-N content. The change of the pH, TN and NO₃^--N content in soil was the main factor affecting the community structure of AOA with the different grazing forms. The stocking of Tibetan spiced pig had more significant effect on the AOA and AOB community. The change of soil environmental conditions caused by grazing was an important factor leading to the change ofammonia-oxidizing microorganism communities.