The non-reference imaginary component method is theoretically and tech nologically rather sophisticated, and the DDW -1 type nonreference imagi nary component instrument designed by Wuhan College of Geology is at pres-tiat the only China-made electromagnetic device. This instrument was used by the Geophysical and Geochemical Prespecting Party of Zhejiang Province to conduct test in mining areas and examine geophysical and geochemical anoma lies for five years with satisfactory geological results. In this paper, the exper imental work carried out in five mining areas have been described.