Nanpanjiang Basin is located in the junction area of the Tethys and Pacific Domains. Thick clastic sediments are developed in the Malipo Babu area, and therefore they are of important significance because of direct contact relationship with Babu ophiolite. Due to lacking of precise isotopic dating evidence, these sediments are still in great controversy. This study first reported the LA- ICP- MS dating age of 226±1 Ma (n=17, MSWD=1.1) for zircons from the tuff above these sediments. Combined with paleontological evidence and contact relationship, it can be confirmed that these clastic sediments are Middle- Upper Triassic Banna- Lanmu- Pinzhai Formations. Onshore- tidal- flat facies sedimentary rocks were firstly discovered, which contains quartzose fine- grained conglomerate, quartzose sandstone, fine sandstone. Sedimentary structures such as parallel bedding, wave- ripple cross beddings, lenticular beddings and interfered ripples are well developed. The evolution from huge succession of deep- water siliciclastic rocks of the Middle Triassic (Bannan- Lanmu Formation) to shallow water sediments of late Triassic (Pingzhai Formation) represents the tectonic evolution of Nanpanjiang forland basin in the Middle- Late Triassic. The unconformity between Ladinian (Gejiu Formation) and Carnian (Pingzhai Formation) represents the Indosinian orogeny II.