A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, designated X1, was isolated from the permafrost region of Qilian Mountains in northwest of China. Phylogenetic analyses of 16S rRNA gene sequence revealed that strain X1 was a member of the genus Sphingomonas and shared the highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082 (96.9 %), followed by Sphingomonas glacialis CGMCC 1.8957 (96.7 %) and Sphingomonas alpina DSM 22537 (96.4 %). Strain X1 was able to grow at 15-30 °C, pH 6.0-10.0 and with 0-0.3 % NaCl (w/v). The DNA G+C content of the isolate was 64.8 mol%. Strain X1-contained Q-10 as the dominant ubiquinone and C ω7 c, C ω7 c, C and C 2-OH as the dominant fatty acids. The polar lipid profile of strain XI-contained sphingoglycolipid, phosphatidylglycerol, phosphatidylethanolamine, one unidentified glycolipid and two unidentified phospholipid. Due to the phenotypic and genetic distinctiveness and other characteristic studied in this article, we consider X1 as a novel species of the genus Sphingomonas and propose to name it Sphingomonas qilianensis sp. nov. The type strain is X1 (=CGMCC 1.15349 = KCTC 42862). [ABSTRACT FROM AUTHOR]