Among a large collection of Taiwanese soil isolates, a novel Gram-variable, rod-shaped, motile, endospore-forming bacterial strain, strain V10537(T), was subjected to a polyphasic study including 16S rRNA and gyrB gene sequence analysis, DNA-DNA hybridization experiments, cell wall peptidoglycan type, cellular fatty acid composition analysis and comparative phenotypic characterization. 16S rRNA gene sequence analysis indicated that the organism belonged to the genus Paenibacillus. Strain V10537(T) possessed meso-diaminopimelic acid as the diagnostic diamino acid of the peptidoglycan. It contained menaquinone MK-7 as the predominant isoprenoid quinone and anteiso-C(15 : 0) (53.6 %) and C(16 : 0) (19.0 %) as the major fatty acids. Phylogenetically, the most closely related species to strain V10537(T) were Paenibacillus pabuli, Paenibacillus xylanilyticus, Paenibacillus amylolyticus, Paenibacillus barcinonensis and Paenibacillus illinoisensis, with 16S rRNA gene sequence similarities of 99.5, 98.8, 98.3, 98.2 and 98.1 % to the respective type strains. The gyrB gene sequence similarities between strain V10537(T) and these strains were 76.9-85.0 %. DNA-DNA hybridization experiments showed levels of relatedness of 8.5-45.6 % between strain V10537(T) and these strains. The DNA G+C content of strain V10537(T) was 46.7 mol%. Strain V10537(T) was clearly distinguishable from other Paenibacillus species and thus represents a novel species of the genus Paenibacillus, for which the name Paenibacillus taichungensis sp. nov. is proposed. The type strain is V10537(T) (=BCRC 17757(T) =DSM 19942(T)).