A yellow-pigmented, Gram-negative, aerobic bacterial strain, designated 5YN10-9(T), was isolated from a wetland, Yongneup, of the Inje region, Korea. Cells were motile by means of one polar flagellum. Based on 16S rRNA gene sequence analyses, strain 5YN10-9(T) was shown to be related to the genera Azoarcus, Azovibrio, Thauera and Zoogloea, showing moderate sequence similarities of 90.2-93.3, 92.7, 90.9-93.3 and 92.4-92.6% to members of these genera, respectively. Its distinct phylogenetic position and the low 16S rRNA gene sequence similarity values toward the closest related genera support the inclusion of this novel isolate in a new genus. The major isoprenoid quinone was ubiquinone 8 (Q-8). The predominant cellular fatty acids were C(16:0) and summed feature 3 (comprising C(16:1)omega7c and/or iso-C(15:0) 2-OH). The DNA G+C content was 59.3 mol%. The results of phenotypic, chemotaxonomic and phylogenetic analyses indicate that strain 5YN10-9(T) represents a novel species of a new genus within the family Rhodocyclaceae, class Betaproteobacteria, for which the name Uliginosibacterium gangwonense gen. nov., sp. nov. is proposed. The type strain is 5YN10-9(T) (=KACC 11603(T)=DSM 18521(T)).