Detailed analyses of sedimentary facies of the Neogene Xiayoushashan Formation in HongliuquanYuedong area，Qaidam Basin，have been made based on the sequence stratigraphic studies. The alluvial fan，fan deltaic，braided fluvial deltaic，lacustrine and turbidite facies were developed during the deposition of the Xiayoushashan Formation. The development characteristics and distribution of the sedimentary facies were analyzed. The planar distribution of the sedimentary facies was analyzed in detail based on the 4 thirdorder sequences identified. During the deposition of sequenceⅠ，the alluvial fan and fan deltaic facies were developed in the northwestern area，while the central western area was dominated by braided fluvial deltaic facies. During the deposition of sequence Ⅱ，the distribution framework of sedimentary facies is similar as sequence Ⅰ. During the deposition of sequence Ⅲ，the distribution extent of the alluvial fan and fan delta in the northwestern area shrank，while the braided fluvial delta in central western area expanded and the area was larger than that in the former stage. During the deposition of sequence Ⅳ，the alluvial fan was developed in the northwestern area，the braided fluvial delta in the central western area stretched quickly to the east，and the braided fluvial delta front reached the center of the study area. Due to tectonic uplifting，the lacustrine basin experienced an evolution process and the depocenter shifted eastwards during the deposition of the Xiayoushashan Formation.