A series of experiments have been made on samples collected from the Shihongtan deposit, southwestern part of the Turpan-Hami Basin in northwestern China, i. e. (1) Extracting organic matter from rocks with CHC13; (2) Extracting organic matter from rocks with CS2-NmP; and (3) Humic substance extracting and separation. Uranium content was analyzed in the extracted organic matters. It was found that the uranium content level in these matters increased to some extent in accordance with the above experimental sequence, with the fulvic acids having the highest uranium content. It illustrates that in the course of uranium deposit formation, the organic (humic substance and bentum ) adsorption plays a partial role. The major player is fulvic acid (FA), which migrates in the form of complexing with uranyl. From the experiment and analysis, the authors believe that the complexing and adsorption of humic substance (humus) are closely linked in the course of uranium migration.