[en] The extraction behavior of thorium from Baotou iron ore with primary amine N1923 levextrel resins by a micro-column was investigated under the decompression technology. Thorium was adsorbed on the micro-column conditioned by 3 mol L^-1 HCl solution before use. The washing liquor of 0.5 mol L^-1 H₂SO₄-0.1 mol L^-1 H₃PO₄ solution was used to wash impurity elements and the solution of 3 mol L^-1 HCl was used as the eluent for thorium. The method was applied to analyze thorium in the Baotou iron ore sample. The relative standard deviations of thorium in R-715 standard sample, Baotou main ore standard sample and Baotou west ore were of 0.49%, 1.63%, 1.16%, respectively. The accuracy of the method was satisfactory. (author)