Objectives：The Lantan section is located on the southwestern margin of the Yangtze platform. Because of its special paleogeographic position, the research of the Lantan section has great significance for the biostratigraphic subdivision and stratigraphic comparison on the southwestern margin of the Yangtze platform. Methods: The main methods of this investigation are surveying section and conodont biostratigraphy in detail. At the same time, we study the characteristics of fish microremains at the Lantan section. Results: Three types of Actinopterygii teeth and Ostracods Cavellina jangyouensis were discovered in the bed 6 of the Lantan section. Elasmobranchii scales and two types of Actinopterygii teeth were discovered in the bed 12. Abundant of Trachyceras sp. were discovered in the bed 14. Two conodont zones have been established from bottom to top: Paragondolella polygnathiformis Zone and Paragondolella tadpole Zone. Conclusions: There are two types of scales and five types of teeth at the Lantan section from the Zhuganpo Formation, Xingyi, Guizhou Province. According to the characteristics of conodont, the boundary between Ladinian and Carnian is defined at the bottom of the bed 12. It can help to build the biostratigraphica framework for the Middle—Upper Triassic boundary nearby.