A Gram-positive, aerobic, non-motile and pale yellow colour actinobacterial strain, designated SYP-B575(T), was isolated from rhizosphere soil of Panax notoginseng. The optimal growth of the strain was found to occur at 28 °C, pH 7.0 and without NaCl. Phylogenetic analysis indicated that strain SYP-B575(T) clearly belongs to the genus Sinomonas and should be considered as a candidate of novel species within this genus. The 16S rRNA gene sequence similarities between strain SYP-B575(T) and the other Sinomonas type strains ranged from 97.3 to 96.0%. The predominant isoprenoid quinone was identified as MK-9(H2) and the major fatty acids were identified as anteiso-C(15:0) and anteiso-C(17:0). The polar lipids were found to consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and glycolipids. The major cell-wall amino acids were identified as Lys, Ala, Glu, Gly and Ser. The whole-cell sugars were identified as mannose, ribose, rhamnose, glucose and galactose. The G+C content of the genomic DNA was determined to be 66.6 mol%. The DNA-DNA relatedness values between SYP-B575(T) and its closest phylogenetic neighbours were lower than 35.5%. On the basis of this polyphasic taxonomic study, strain SYP-B575(T) represents a novel species of the genus Sinomonas, for which the name Sinomonas notoginsengisoli sp. nov. is proposed. The type strain is SYP-B575(T) (=DSM 27685(T) = KCTC 29237(T)).