The type species "Chaohusaurus geishanensis" was named and described by Yang Zhongjian and Dong Zhiming in 1972, based on a fossil found during the construction of a railway. The generic name refers to lake Chao Hu. The specific name refers to the Geishan location. The holotype, IVPP V 4001, was uncovered in a layer of the Majianshan Limestone Formation dating from the Anisian. It consists of a partial skeleton, containing the skull and the front torso. In 1985 Chen Lizhu named two additional species based on fossils found in the same formation: "Anhuisaurus chaoxianensis" and "Anhuisaurus faciles". However, the generic name had already been preoccupied by the lizard "Anhuisaurus" Hou 1974. Therefore, "Anhuisaurus" Chen 1985 was in 1991 renamed into "Chensaurus" by Jean-Michel Mazin e.a. In 1998, Ryosuke Motani e.a. established that the "Chensaurus" fossils represented remains of juveniles, with those of "C. faciles" being the youngest, and that these formed a growth series with "Chaohusaurus". This implied that the known material of "Chaohusaurus" was increased with the specimens AGM P45-H85-25, the holotype of "Chensaurus chaoxianensis"; AGM P45-H85-25, the holotype of "Chensaurus faciles"; and the front flippers IVPP V 11361 and IVPP V 11362. In 2001 a detailed description of the osteology of "Chaohusaurus" was published by Michael Maisch.