Abstract: Bigrlyi Uranium Deposit is located in the northern margin of Ngalia Basin, Northern Territory, Australia and it is a typical sandstone-hosted uranium deposit, which consists mainly of orebodies A2/A3, A4, A7 and A15. The Ngalia Basin is an asymmetrical residual intermontane basin of steep in the north and gentle in the south with the basin cover composed dominantly of Neoproterozoic （-850 Ma） and Palaeozoic terrestrial sedimentary successions. The Mount Eclipse Sandstone of Devonian to Carboniferous age lies unconformably on the underlying stratigraphy in response to the Alice Springs Orogeny (ASO) of Late Ordovician to Late Carboniferous age and it is the primary ore-bearing horizon for the sandstone-hosted mineralization in the Ngalia Basin. The Mount Eclipse Sandstone is deposited in the environment of foreland basin, where the fluvial, fan delta or delta and lake sedimentary systems are developed. The ore-bearing rocks are composed dominantly of grey arkosic sandstone and greywacke in the unit C of Mount Eclipse Sandstone with uranium minerals consisting dominantly of pitchblende and coffinite and with gauge minerals consisting of quartz, K-feldspar and a small amount of clay minerals. The sandstone-hosted uranium mineralization in the Ngalia Basin is controlled dominantly by the uranium source, depositional environment and structure. The compressional tectonics and basement uplift during the depositional and diagenetic period resulted in the formation of a set of ore-bearing horizons favorable for the uranium mineralization, where uranium is enriched initially and participated locally to form the uranium mineralization. The ore-bearing horizons are uplifted and exposed at the surface due to the post-depositional continuous compression and thrusting and the uranium and oxygen bearing water from the provenance area infiltrated into these horizons to form roll-like or “tabular” uranium-enriched orebodies in redox transition zones.