MethArDB is a curated database and integrated dataset dedicated to methanogenic archaea. This Zenodo repository contains the primary datasets supporting the MethArDB platform, including: • Accession_List.xlsx: genome assembly metadata of methanogenic archaea collected from NCBI GenBank and RefSeq databases. • Plasmid_List.xlsx: curated plasmid records associated with methanogenic archaea. • Phage_List.xlsx: curated virus/phage records associated with methanogenic archaea. • Raw_Sequences.zip: archived sequence files associated with the dataset. • README.txt: dataset documentation and usage instructions. The dataset covers publicly available records released between 1999 and 2025 and supports studies in methanogen diversity, phylogeny, methane metabolism, anaerobic digestion, environmental microbiology, and archaeal genomics. Associated database website:http://methardb.cn License:Creative Commons Attribution 4.0 International (CC BY 4.0)