Based on the petrological characteristics, sandstone detrital composition, analysis of heavy minerals assemblages and U-Pb zircon age, the sedimentary characteristics and provenance evolution of Sha 1 member of Neogene Shawan Formation in Chepaizi Uplift are discussed. The results show that there were double-provenance systems of north and south in Chepaizi Uplift and Sha 1 member of Shawan Formation was dominated by coarse clastic deposits. In the sedimentary period of first sand group of Sha 1 member, the Zaire Mountains was the northern provenance, with small-scale fan delta deposits. The Central Tianshan and North Tianshan orogenic belts were the southern provenances, with braided river delta deposits. In the sedimentary period of second sand group of Sha 1 member, the sediments derived from the Central Tianshan were weakened, while those from the North Tianshan were strengthened, and the water body of the basin was deepened. Small shore-lake beach bars were distributed in front of the southern braided river delta. The main reason for the variation of the provenance in the south may be that the Tianshan experienced a strong extrusion and uplift process in the middle Miocene due to the remote collision between the Indian plate and the Eurasian plate, resulting in the uplift of the North Tianshan, which provided the provenance for Chepaizi Uplift.