The type specimen of Y. shangyouensis had a skull 82 cm (2.7 ft) long, and its total body length was estimated at about 8 m (26 ft). Another specimen, assigned to the new species Y. magnus, was even larger, with a skull length of 1.11 m (3.6 ft). It may have been up to 10.8 m (35.4 ft) long, and weighed as much as 3.4 metric tons (3.7 short tons). There was a bony ridge on its nose and multiple hornlets and ridges, similar to Ceratosaurus.
Yangchuanosaurus was a large, powerful meat-eater. It walked on two large, muscular legs, had short arms, a strong, short neck, a big head with powerful jaws, and large, serrated teeth. It had a long, massive tail that was about half of its length. Its feet had three toes, each with a large claw. Its arms were short, and it had three clawed fingers on each hand.
The Land Before TimeIn The Land Before Time VI: The Secret of Saurus Rock, a pair of stylistic Yangchuanosaurus appear during the song The Legend of the Lone Dinosaur, in a fantasy sequence.
- Despite the fact that they are supposedly intended to be Yangchuanosaurus, they look more like Tyrannosaurus due to their fingers, and their general lack of traits that signify them as Yangchuanosaurus.