A novel bacterium SX-49(T) with nitrogen-fixing capability was isolated from the rhizosphere soil of maize. Phylogenetic analysis of nifH gene fragment and 16S rRNA gene sequence revealed that the strain SX-49(T) is a member of the genus Pae-nibacillus. Values of 16S rRNA gene sequence similarity were highest between SX-49(T) and P. jamilae DSM 13815(T) (97.0%), P. brasiliensis DSM 14914(T) (97.8%), P. polymyxa DSM 36(T) (97.5%), and P. terrae DSM 15891(T) (98.8%). The similarity between SX-49(T) and other Paenibacillus species was < 97.0%. DNA-DNA hybridization values between strain SX-49(T) and the four type strains were P. jamilae DSM 13815(T):40.6%, P. brasiliensis DSM 14914(T):27.9%, P. polymyxa DSM 36(T):29.2%, and P. terrae DSM 15891(T):66.4%. The DNA G+C content of SX-49(T) was 46.4 mol%. The predominant fatty acids were anteiso-C-15:0, C-16:0 and iso-C (16:0). The predominant isoprenoid quinone was MK-7. The genome contains 5628 putative protein-coding sequences (CDS), 6 rRNAs and 56 tRNAs. The phenotypic and genotypic characteristics, DNA-DNA relatedness, and genome features suggest that SX-49(T) represents a novel species of the genus Paenibacillus, and the name Paenibacillus maysiensis sp. nov. is proposed.