A Gram-stain-negative, rod-shaped, motile bacterium, designated AER10T, was isolated from the roots of Ammodendron bifolium collected from Takeermohuer desert in Xinjiang Uygur Autonomous Region, northwestern China. Growth was found to occur from 10 to 45 °C, at pH 5.0-9.0, and could tolerate up to 10 % (w/v) NaCl. 16S rRNA gene sequence result indicated that the strain AER10T belongs to the genus Alcaligenes and was closely related to Alcaligenes aquatilis (98.4 %), Alcaligenes faecalissubsp. parafaecalis (98.4 %), Alcaligenes faecalissubsp. faecalis (98.1 %) and Alcaligenes faecalissubsp. phenolicus (97.9 %). However, the DNA-DNA hybridization values between the strain AER10T and the above strains were less than the threshold value (below 70 %) for the delineation of genomic species. The DNA G+C content was 53.3 mol%. Ubiquinone-8 (Q-8) was the only quinone system present. The major fatty acids were summed feature 8 (C18 : 1ω7c, 25 %), C16 : 0 (24.2 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c, 19.3 %) and cyclo-C17 : 0 (10.5 %). The polar lipid profile of the strain AER10T consists of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, two unidentified aminolipids and five unknown polar lipids. On the basis of the evidence presented in this study, strain AER10T is a representative of a novel species in the genus Alcaligenes, for which the name Alcaligenes endophyticus sp. nov. is proposed. The type strain is AER10T (=DSM 100498T=KCTC 42688T).