Wenxinia marina Ying et al. 2007 is the type species of the genus Wenxinia, a representative of the Roseobacter group within the alphaproteobacterial family Rhodobacteraceae, isolated from oilfield sediments of the South China Sea. This family was shown to harbor the most abundant bacteria especially from coastal and polar waters, but was also found in microbial mats, sediments and attached to different kind of surfaces. Here we describe the features of W. marina strain HY34(T) together with the genome sequence and annotation of strain DSM 24838(T) and novel aspects of its phenotype. The 4,181,754 bp containing genome sequence encodes 4,047 protein-coding genes and 59 RNA genes. The genome of W. marina DSM 24838(T) was sequenced as part of the activities of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project funded by the DoE and the Transregional Collaborative Research Centre 51 (TRR51) funded by the German Research Foundation (DFG).