The Quaternary sediments in the Sanhu area of Qaidam Basin is the product of migration of the basin depositional center from west to east under the tectonic movements at the end of Tertiary. Through the field survey, the authors found that the Quaternary sediments in the study area are apparently asymmetrical in distribution. Through analyses of water system, reservoir lithology, mineral assemblages, paleosalinity, heavy minerals, argillaceous content and sand content, and seismic reflection features as well as reservoir inversion, the authors further found that these sediments came from two sources. Finally, The studies show that the Taidong nose-like structure should be a favorable target for the future exploration.