The Formosan macaque has a body length of 36~65cm, tail length at 26~46cm and weight of 5~12kg, where some grown males can reach 18kg. The species has a pouch-like cheek with small auricles; the body is covered in greyish brown hair and the belly is colored in greyish white with pads colored in distinct reddish brown at buttocks. During the estrous period, the hip skin of the female swells with a distinct red color.
The Formosan macaque distributes over coniferous forests, broad-leaved forests, mixed forests and fruit farms at low-to-high altitude over the entire Island. The species occupies forests for main activity and sleeps on trees or rocks. The herd is a matrilineal society, but the activities take place around one grown male as the center. A herd contains approximately several to dozens of Formosan macaque. The diet includes fruits, seeds, shoots, tender leaves and insects.