[en] Factors influencing depth distribution of radium and its transfer through NORM contaminated profiles in the Syrian oil fields have been studied. Leaching results have shown that radium is not soluble by rain water and does not transfer vertically; radium is transferred from the upper layers to deeper layers by erosion of the contaminated soil caused by rain water. This soil erosion process is linked with the mineralogical composition of the contaminated soil, where soils containing high concentrations of gypsum such as those seen in El-ward and Omar fields, have contributed significantly to the radium transfer to deeper layers. This also confirms that transferred radium is linked with soil particle size erosion. On the other hand, the influence of sodium chloride amount in the upper layers was very clear on vertical distribution of ²²⁶Ra. (author)