[en] The effect of humic acid contained in uranium ores on processing uranium ores is presented. Some characters of humic acid are described. Some harms, such as lowering the percolation rate in heap leaching with sulphuric acid, decreasing the extraction capacity of amine extractants, decreasing the adsorption capacity of resins, raising difficulties in phases separation, promoting emulsification in extraction and stripping, raising cost of organic phase, increasing NaOH consumption and reducing precipitation efficiency of uranium, are explained. The methods of removing humic acid are given