A coccus-shaped, non-spore-forming actinobacterium, designated strain 4Q3S-3, was isolated from surface-sterilized bark of the mangrove plant Kandelia candel collected from Cotai Ecological Zones in Macao, China, and tested by a polyphasic approach to clarify its taxonomic position. This actinobacterium was Gram-stain-positive and aerobic. Neither substrate nor aerial mycelia were formed, and no diffusible pigments were observed on the media tested. Strain 4Q3S-3 grew optimally without NaCl at 28-30 °C, pH 7.0-8.0. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain 4Q3S-3 belonged to the genus Friedmanniella and shared the highest 16S rRNA gene sequence similarity with Friedmanniella flava W6T (96.57 %). The DNA G+C content of strain 4Q3S-3 was 69.5 mol%. The cell-wall peptidoglycan contained LL-2,6-diaminopimelic acid, and MK-9(H) was the predominant menaquinone. The polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, unidentified glycolipid, amino lipids and two unidentified phospholipids. The predominant fatty acids were anteiso-C, iso-C and iso-C. Based on phylogenetic, phenotypic and chemotaxonomic data, strain 4Q3S-3 represents a novel species of the genus Friedmanniella, for which the name Friedmanniella endophytica sp. nov. is proposed. The type strain is 4Q3S-3 (=DSM 100723=CGMCC 4.7307).