Genus: Chaoyangsaurus ZHAO, CHENG & XU, 1999
Etymology: In reference to Chaoyang County, China, were the specimen was found, and Greek, sauros, "lizard."
= Chaoyoungosaurus [Anonymous] 1981-1982 [nomen nudum; transliterated from Japanese]
= Chaoyoungosaurus ZHAO, 1983 (sic)
= Chaoyangosaurus ZHAO & CHENG, 1983 (nomen nudum)

Species: youngi ZHAO, CHENG & XU, 1999
Etymology: The specific name is in memory of the founder of vertebrate paleontology in China, C. C. Young.
= Chaoyangosaurus liaosiensis ZHAO, 1985 (nomen nudum)
= Chaoyangosaurus liaosiensis ZHAO & CHENG, 1983 (nomen nudum)

Holotype: IGCAGS V371 (IVPP V11527?)

Locality: Chaoyang County, 43°02'N, 90°45'E, Western part of Liaoning Province, North China.

Horizon: Tuchengzi Formation.

Biostratigraphy:

Age: Middle or Late Jurassic.

Material: Fragmentary skull missing the dorsal part of the skull, nearly complete mandible, complete axis, an isolated cervical vertebra, and 5 articulated cervicals, a fragmentary humerus and scapula.