Yunnanilus macrogaster is a hypogean species of stone loach endemic to China.

It is a demersal species and the waters where it was found were densely vegetated,[1] it feeds on worms and insects.

The caudal peduncle is around 1.4 times as long as it is deep and its eyes have a diameter of slightly less than one-fifth of the head length.

The body is yellowish with an irregular pattern of brown spots on its back and flanks with the dorsal surface of the head being darker and there is a dark patch on the operculum to the rear of the eye.

[5] The specific name macrogaster means "large stomach", referring to the swollen bellied appearance of this species.