A Gram-stain-positive, rod-shaped, endospore-forming bacterium, strain CAU 9038(T), was isolated from a tidal-flat sediment of DaeYiJac Island, Republic of Korea, and its taxonomic position was investigated using a polyphasic approach. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol, the major isoprenoid quinone was MK-7 and the dominant cellular fatty acid was anteiso-C(15 : 0). The DNA G+C content was 51.6 mol%. 16S rRNA gene sequence analysis showed that the strain belonged to the genus Paenibacillus, with <96.1 % sequence similarity to type strains of Paenibacillus species with validly published names. The most closely related type strains to CAU 9038(T) were Paenibacillus thailandensis S3-4A(T) (96.1 % similarity) and Paenibacillus agaridevorans DSM 1355(T) (95.3 %). The phenotypic, chemotaxonomic and genotypic data clearly indicated that strain CAU 9038(T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillus chungangensis sp. nov. is proposed. The type strain is CAU 9038(T) (=KCTC 13717(T) =CCUG 59129(T)).