Currently, sandstone- hosted uranium deposits are globally the most widely used and promising uranium resource and also the most important industrial uranium resource in China. This review shows the latest data on the distribution and composition of the global uranium resources and emphasizes the significance of the sandstone- hosted uranium resource within whole uranium resources both globally and in China. The enrichment mechanisms of U(VI) by microorganisms reductively and non- reductively revealed in the laboratory and the evidence for microbial mineralization in actual sandstone- hosted uranium deposits are also summarized. Experimental studies have revealed both reductive and non- reductive enrichment mechanisms of U(VI) by microorganisms. U(VI) bioreductive enrichment has been intensively studied, in which cytochromes, pili and electron shuttle are significant. U(VI) non- bioreductive enrichment includes extracellular biosorption, complex- precipitation and intracellular bioaccumulation. The evidences for microbial mineralization in actual sandstone- hosted uranium deposits are classified as direct and indirect. Direct evidence includes morphology, phosphorous content and nano- crystals of the uranium minerals, and indirect evidence includes sulfur isotope composition of the ore- stage pyrite, carbon isotope composition of the ore- stage calcite and corresponding biomarkers in the hydrocarbon inclusions. The emphasis in future studies should be on the application of microzone experimental methods to this field, to prospect in overlying strata in the petroleum- /coal- bearing basins, and to explore more proper indexes and systems to quantitatively assess the microbial mineralization in sandstone- hosted uranium deposits.