Mangrove ecosystem is indispensable in maintaining biodiversity and removing pollutants to keep the ecological balance of coastal zone. Archaea, ubiquitous in mangrove sediments, play an important role in the biogeochemical cycles of elements. Archaea possess carbon metabolic versatility by fixing CO₂, participating in the methane cycle, producing acetic acid, and degrading proteins, carbohydrates and other organic matter. However, knowledge about metabolism of archaea in mangrove sediments is still lacking. Rapid development of high-throughput sequencing technology has promoted the discovery of a variety of new archaea phyla, indicating various metabolic potentials in carbon metabolism. This review briefly outlined the main phyla of archaea and their geographical distribution, summarized the latest advances on understanding of carbon metabolic versatility by archaea, and highlighted the ecological patterns and functional traits of these archaea in mangrove ecosystems, providing a foundation for further research on the more detailed metabolic mechanisms of archaea.