Hebius maximus, the western China keelback, is a species of snake of the family Colubridae. The snake is endemic to Southwestern China (Chongqing, Sichuan, northwestern Guizhou). Originally described as a subspecies of Amphiesma sauteri (=Hebius sauteri), its validity has been doubted; however, it was revalidated by a 2022 study based on morphological and molecular evidence. The evidence even warranted the recognition of Hebius maximus as a full species.
The specific name maximus refers to this taxon having the highest count of ventral scales among what at the time were the three subspecies of H. sauteri.
Hebius maximus is a small to medium-sized snake, reaching in total length. The tail is relatively long, 25–33% of the total length. Dorsal colouration is reddish-brown or grayish brown, while the ventrum is cream white. An ill-defined dark olive dorsal streak scattered with black spots runs from neck to tail.
Hebius maximus occurs in subtropical mountain regions at elevations of about 812m–1200mm (2,664feet–3,900feetm) above sea level in coniferous forests, large forest clearings, and agricultural areas. It is diurnal, active at dusk. Its prey includes earthworms, slugs, and tadpoles.