The evaluation of ore-prospecting effects in thick overburden areas has long become a difficult point in geological exploration work. Based on method experiments in the Erentaolegai silver ore district of Xin Barag Right Banner, the authors have reached the conclusion that, in arid and airborne sand thick overburden areas, anomalies can be discovered by adopting the sampling depth of 40 cm, grain size of —140 mesh, ionic conductivity with stirring time of over 1 min, heat-release mercury with temperature of 800℃ and the measurement of water-soluble state and adsorption state of the element active state. In Adunchulu and Harule Obo prospective areas, the anomalies delineated by these methods are quite consistent with those delineated by routine soil geochemical survey and have obvious concentration centers.