Abstract: The fossil fishes described here were collected from the Upper Shaximiao Formation of Zizhong, Sichuan, and are referred to a new genus and species, Tianfuichthys spinodorsalis, of the Semionotidae. Tianfuichthys resembles Semionotus in many respects, and Neolepidotes in some respects. It is characterized by extraordinarily spine-shaped dorsal ridge-scales, large parietals, few suborbitals, lacking fringing fulcra, and distinguished from all the known genera in the family. By Tianfuichthys and known fossil fishes, the age of the fish-bearing beds is probably Middle Jurassic. This new discovery is of great signific ance to the study of the biostratigraphy in Sichuan Basin.