A novel aerobic actinomycete, designated HA11110(T), was isolated from a mangrove soil sample collected in Haikou, China. It formed white aerial mycelium and pale yellow substrate mycelium on Gause's synthetic agar no. 1. Scanning electron microscopy revealed that cells of HA11110(T) produced straight to spiral spore chains with spiny spores. Chemotaxonomic tests showed that the cell wall contained LL-diaminopimelic acid and the major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C14 : 0.16S rRNA gene sequence similarity showed that strain HA11110(T) belonged to the genus Streptomyces, most closely related to Streptomyces fenghuangensis GIMN4.003(T) (99.1%), Streptomyces nanhaiensis SCSIO 01248(T) (98.8%) and Streptomyces radiopugnans R97(T) (98.8%). However, DNA-DNA hybridization studies of strain HA11110T with these three closest relatives showed relatedness values of 58.4, 49.7 and 47.2%, respectively. On the basis of phenotypic and genotypic data, strain HA11110(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces mangrovi sp. nov. is proposed. The type strain is HA11110(T) ( = CGMCC 4.7117(T)= DSM 42113(T)).