Abstract:Methanogens are one kind of archaea that can use simple compounds to generate methane in anaerobic environments. Thanks to the rapid development of the Next Generation Sequencing, metagenomics has revealed plenty of novel potential methanogens, including Methanomassiliicoccales (RC-Ⅲ), Methanofastidiosa (WSA2), Methanonatronarchaeia, Bathyarchaeota, Verstraetearchaeota and Geoarchaeota. Genomic analysis shows that ubiquitous novel methanogens harbor unique methane metabolism pathway indicating that they might play unrecognized important roles in global carbon cycle. To better understand these novel methanogens, this review summarizes the latest researches on the classification, phylogenetic status, methane metabolic mechanism, ecological distribution, isolation and cultivation of these novel methanogens, highlighting their research directions in the future.