In this study, the diversity, community structure and distribution of anammox bacteria in sediments from five sites of the ECS and YS were explored by using both the 16S rRNA and hzo functional gene biomarkers. A high diversity of anammox bacteria in the studied sites with Candidatus is observed. Scalindua being the dominant group of anammox bacteria. With 16S rRNA gene primers, an inimitable Candidatus. Scalindua phylotype was identified, putatively represented a novel species, and tentatively named “Candidatus. Scalindua flavia”. In addition, three other distinct clades were also detected with a discrete clustering in the consensus tree. Statistical analysis of environmental variables indicated that NH4+ and PO4 3- are positively correlated to shape the differential distribution of anammox bacteria in different environments.