Abstract: The materials dealt with in this paper were collected from the Luolou Formation of Zuodeng area, Tiandong County of Guangxi Zhuang Autonomous Region, China (Figs. 1 ,2). They include three hybodontoid species: Hybodus zuodengensis (Yang et al., 1984), H. yohi (Yang et al., 1984) and Polyacrodus tiandongensis sp. nov., and an indeterminate osteichthyan fish. The two species of Hybodus were initially identified as conodonts — Pachycladina zuodengensis and Pseudogondalella yohi by Yang et al. in 1984. This is the first report on the occurrence of marine Early Triassic Hybodontoidea in China. With the reassignment and new discovery of these fishes, a fish assemblage (Hybodus zuodengensis-H. yohi Zone) is established, which is the only Triassic fish zonation in China. The age of this zonation is Early Triassic (early Spathian of Olenekian Stage) for it makes its appearance just in the conodont Neospathodus homeri-N. t riangularis Zone.