Abstract: By the studies of the fluid inclusion, it is found that the high concentrated areas of the ore-for ming solution are generally where the main (rich) orebodies occur. Open the fluid inclusion by heat explosion, extract the ore-forming solution, measure the relative density of the ore-forming solution through its electric conductivity, and apply the results to the test of mineralization and ore-search by geological analogy. It is proved that the electric conductivity of ore-forming solution can be used to seek for ore-forming fractures, to select the best mineralization section, to distinguish industrial and non-industrial auriferous quartz veins, to reflect the rich or poor levels of orebodies, to evaluate the stability of orebodies, to judge the denuding levels of ore veins, and to prospect the mineralization in depth.