Xihulitu Basin is an Early Cretaceous downfaulted basin and the Damoguaihe Formation of lower cretaceous is its depositional cover. Influencing by syndepositional fault in southern margin, the alluvial fan and fan delta facies are developed mainly in the southern part of the basin while the braided stream and delta facies are developed in its northern part, only alluvial fans developed in its upper strata. However, the very thick lacustrine sediments are dominant in the central part of the basin. Studies of sedimentology show that the Damoguaihe Formation can be further subdivided into three members. The first member is developed in the beginning of downfaulted period during which  alluvial fan, stream and delta facies are mainly developed; and the second member,  which is the main component of the depositional cover, is formed in the extensively enlarged period of the lacustrine basin with very thick lacustrine mudstone, while the stream and delta facies are dominant at the end of this period. However, the third member features with the large-scale alluvial fan facies, which shows that the basin enters the shrinking stage of its evolution. The above characteristics of the Damoguaihe Formation reveal that the sedimentary facies plays an important role in controlling both the distribution and the type of mineralization of the epigenetic sandstone-type uranium deposits in the region. The stratigraphic structure of “coarse - fine - coarse” in granularity from bottom to top of the cover determines that the uranium mineralization mainly occur in the upper of depositional cover, that is, in the coarse detrital sediments in the upper of the second member and in the third member; main ore-bearing beds are in the alluvial fan, braided stream and delta facies of the second and third members, and the U-bearing host rocks are mainly the glutinite and sandstone of granule-supported massive and crossbedding litho-facies,  which is abundant in organic matter and good in infiltration. At the same time, due to lack of the mudstone layer, which usually acts as groundwater confining bed, the uranium mineralization in the region is typically a kind of phreatic oxidized mineralization with vertical zoning, while phreatic - interlayered oxidized mineralization  is only developed locally.