This paper is adapted from the results of 1:25,000 high power IPreconnaissance over Daheishan district, in central Jilin Province. Based on the macroscopic characteristics of the polarization field with special reference to the geological data available, fairly good results were achieved in geological mapping, e. g., in defining fracturel, features and stratigraphical conditions as well as in discriminating strata, and intrusives etc. The general geological picture constructed on IPinformation furnishes a better insight into the ore-controlling geology, helps to locate the favorable areas of mineralization, thus reduceing the target area for prospecting, and, according to the actual geological conditions, sifting out the best anomalies for follow-ups so as to provide prospective areas for further exploration.