Abstract: The Zhesi Formation can be divided into siltstone-shale member in the lower part and conglomerate-sandstone member in the upper part in Zhuolunyinnoer, southern Sonid Left Banner, Inner Mongolia, representing overbank deposition of middle fan subfacies and proximal rapid deposition of inner fan subfacies, respectively and implying a paleogeographic framework characterized by alluvial fan in intracontinental basin with the shallow water and oxidation conditions. Geochronological research on detrital zircon reveals a complex provenance containing the Xing'an-Ailigemiao block, the early Paleozoic arc belt and late Carboniferious and early Permian plutons. The youngest detrital zircon peak age of 281Ma from the Zhesi Formation and another age of 248±3Ma from diorite porphyrite that intruded into the Zhesi Formation were obtained in the study area, which shows that the formation age of the Zhesi Formation is between the Middle Permian and Early Triassic. Regional geology analysis reveals that there existed middle to Late Permian terrigenous clastic sedimentary basins in the central and western parts of the Xing-Meng orogenic belt (XMOB). They were isolated from each other with different sedimentary sequences, suggesting "basin-and-ridge" structure style and intracontinental extensional tectonic setting during the Permian in the XMOB.