The Puyi area is located in the Middle of upper Yangtze, southeast margin of Sichuan basin. The Late Triassic clasolite record the evolution information of the upper Yangtze foreland basin, which is an ideal object for studying the coupling relationships between sedimentary basins and orogenic belts in the eastern margin of the basin. The Erqiao Formation is mainly composed of delta sandstone. The provenance of cross bedding restoration is mainly from the East. Sandstone detrital are mainly composed of magmatic detrital and metamorphic detrital. Detrital heavy minerals are mainly composed of zircon, tourmaline, rutile, albite, pyrite, garnet, chromite and anatase. In this paper, we determined the zircon tourmaline chemical composition and U- Pb isotope from sandstone of the Erqiao Formation by means of electron microprobe and LA- ICP- MS, further studied the provenance of the Erqiao Formation, and discussed the evolution of the upper Yangtze basin in Late Triassic. The chemical composition of tourmaline shows that it is mainly composed of magnesium tourmaline and black tourmaline, which comes from granite, meta- sandstone, slate etc. The zircon U- Pb ages show detrital zircons of the Erqiao Formation mainly have five peaks at 2662~2380 Ma, 2077~1688 Ma, 840~722 Ma, 475~412 Ma and 293~246 Ma. The first two age peaks account for the largest proportion, showing the characteristics of multiple provenances. Combined with sandstone detrital composition and tourmaline chemical composition, it is inferred that the provenance is mainly from the Neoproterozoic recycle sedimentary area in Fanjingshan area of the Jiangnan orogenic belt. Some provenances may be provided by Kongling area in the north of Yangtze, and a small amount by the Caledonian pyroclastic rocks, the Indosinian- Hercynian Emeishan basalt and contemporaneous intrusive rocks and tuffs. It shows that the front uplift belt of the upper Yangtze foreland basin continued to move southeast in the Late Triassic, and the Jiangnan orogenic belt became the front uplift belt in the middle and late stage, providing the main provenances for the southeast of the basin.