This paper briefly reports a new genus and species of Sauropterygia, Spatulidentatus breviceps, from the Upper Member of the Middle Triassic Guanling Formation in the border area between Yunnan and Guizhou in Southwest China. The new species can be diagnosed by following characteristics: a mall head, accounting for 5% of the total body length; spatulate teeth in both upper and lower jaws; elongated neural spines in dorsal and tail region; a well - developed scapular dorsal wing; a sub-oval coracoid; and a distinctly expanded distal humerus with well-developed condyle. Preliminary comparative analysis shows that the new species may have a relatively close relationship with the basal groups of Sauropterygia, such as Placodontia and Atopodentatus.