AbstractThe stumptail macaque speciesMacaca thibetanaandMacaca arctoidesreplace one another from north to south in subtropical and tropical China. These species differ in external and cranial characters. Neonatal pelage color is pale grayish‐brown inM. thibetanaand whitish inM. arctoides. In adults, ventral pelage is whitish inM. thibetanaand brown inM. arctoides. The forehead and cheeks are thickly furred in adultM. thibetanaand bald inM. arctoides. Facial skin color typically is sexually dimorphic inM. thibetana—buffy in males and reddish in females—and monomorphic inM. arctoides—reddish in both sexes. Head and body length, weight, relative tail length, and relative ear length all tend to average greater inM. thibetanathan inM. arctoides. Skull length, rostral‐postrostral ratio, and relative canine length in males average greater inM. thibetana. than inM. arctoides;relative zygomatic breadth and relative bimalar breadth average greater inM. arctoidesthan inM. thibetana. Reproductive anatomy in both sexes is strikingly divergent in these two species. Although these species are adapted to different climatic zones, many aspects of their natural history are generally similar, as far as is now known. One apparent behavioral difference is thatM. thibetanausually sleeps in caves or rocky crevices, whileM. arctoidesusually sleeps