A Gram-staining-negative, rod-shaped and non-spore-forming bacterium, designated strain 333-1-0411 T , was isolated from a soil sample collected from Namucuo, Tibet Autonomous Region, China and characterized in a taxonomic study using a polyphasic approach. The major fatty acid components of strain 333-1-0411 T were summed feature 3 (C 16 : 1 v7c and/or C 16 : 1 v6c) and C 16 : 0 ; its major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. Q-8 was the dominant ubiquinone, and the G+C content of the genomic DNA was 66.7 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain 333-1-0411 T fell within the evolutionary radiation encompassed by the genus Massilia. The 16S rRNA gene sequence similarities between strain 333-1-0411 T and recognized species of the genus Massilia ranged from 95.4 % to 97.2 %, and the most closely related strains were Massilia flava Y9 T (97.2 %) and Massilia albidiflava 45 T (97.0 %). However, the DNA-DNA relatedness values between strain 333-1-0411 T and M. flava Y9 T and M. albidiflava 45 T were 20.2 % and 27.2 %, respectively. Based on the phenotypic, chemotaxonomic and phylogenetic properties, strain 333-1-0411 T is considered to represent a novel species of the genus Massilia, for which the name Massilia namucuonensis sp. nov. is proposed. The type strain is 333-1-0411 T (5CGMCC 1.11014 T 5DSM 25159 T ).The genus Massilia was first described by La Scola et al.(1998) based on a single isolate from the blood of 25-yearold patient who was immunocompromised with cerebellar lesions. Since then, other strains representing species of the genus Massilia have been isolated from air (Weon et al., 2008, 2009, 2010), water (Gallego et al., 2006 and soil samples (Zhang et al., 2006;Zul et al., 2008;Wang et al., 2012). At the time of writing, 18 species have been described and their descriptions published. The genus Massilia was described to comprise aerobic, Gramnegative, motile, non-spore-forming rods. Summed feature 3 (comprising C 16 : 1 v7c and/or iso-C 15 : 0 2-OH) and C 16 : 0 are the major fatty acids, Q-8 is the predominant isoprenoid quinone and the DNA G+C content is in the range of 63.3-68.9 mol% (Weon et al., 2009).Soil samples were collected from sites located 25 m from the Namucuo Saltwater Lake (30 u 469 270 N, 90 u 529 000 E and 4598 m in altitude) on 15 September 2010 in Tibet Autonomous Region, China. For isolation, the soil sample (1 g) was suspended in distilled water (50 ml) and spread on plates of R2A medium after serial dilution on 20 September 2010. The R2A medium (Niuniu) contained the following (l 21 ): yeast extract 0.5 g, proteose peptone 0.5 g, casein hydrolysate 0.5 g, glucose 0.5 g, starch 0.5 g, sodium pyruvate 0.3 g, dipotassium hydrogen phosphate 0.3 g, magnesium sulphate anhydrous 0.024 g, agar 15.0 g. The pH was adjusted to 7.2±0.2. The plates were incubated at 28 u C for 2-3 days. Single colonies from the plates were purified by transferring them onto new plates of the same medium. The strain, ...