Tianshan forest rat can grow up to 15-23 cm. The fur of the Tianshan forest rat is tight and soft, with dark brown head and back, dark rust-red head and back in some individuals, and light gray or sandy yellow in other parts. The tail of the Tianshan forest rat is very strange: the upper part is dark brown and the lower part is white. The Tianshan forest rat has larger ears, relatively long hind feet, and females have 4 nipples.

Tianshan forest rat is a nocturnal rodent, and they use plant materials in Nest in dry burrows. Their urine helps keep the nest together. This preserves the nests for tens of thousands of years, some dating back to before the last ice age. Due to the limited foraging range of the Tianshan forest rat, their nests consisted of contents representative of the local environment at the time the material was collected.