The Upper Triassic Hagong Formation distributed in Shangri-La area, NW Yunnan consists of terrestrial conglomerate, sandstone, siltstone and mudstone with a lot of chaotic blocks. Chert chaotic blocks yield Middle Devonian to Middle Triassic radiolarian fauna, as well as Middle Devonian tantaculites. All the chert chaotic blocks with various ages were biogenic with Al2O3/(Al2O3+Fe2O3) ratios from 0.58 to 0.96. NASC normalized REE patterns for the chertg are relatively flat with small negative or obvious positive Ce anomaly, while without Eu anomaly, which implies the continental margin basin of depositional environment. The plankton assemblage of radiolarian and tentaculites and the geochemical features indicate that the Garze-Litang basin should have formed before Middle Devonian. The evolution of Garze-Litang basin could be divided into two stages according to the REE characters, including slowly spreading stage from Middle Devonian to early Early Carboniferous and fast spreading and subduction stage from late Early Carboniferous to Middle Triassic. There was still deep-water basin in Late Triassic, even Jurassic.