A coal bed water in Zhaolou coal mine of eastern China contained abundant microbial consortia, which could convert Baiyinhua native lignite to biogenic methane. The major microbes in coal bed water were bacteria (88%) including Proteobacteria and Firmicutes, and the rest of it were assigned to Methanobacterium. Methane generation rate with this microbial consortium was up to 72 mu mol/g coal in 28 d culture. After treatments with the enriched culture, the ash, volatility contents, and hydrophobicity of residual lignite decreased, while its active functional groups containing oxygen and hydrogen increased.