Abstract: Extraction of remote sensing anomaly is an advanced method for prospecting minerals. The method is just rising and its foreground cannot be predicted. From study of application of the American Landsat-7ETM⁺ data in the northern Qilian metallogenicbelt, this paper suggests that the DPT technique is the best in extraction of remote sensing anomalies. However, the technique also has some shortcomings and limitaions. Thus, additional explanation of the remote sensing anomalies are necessary. points out the limitation and various.