This paper explains the results of using new type time-domain induced polarization prospecting system (IPR-12) in exploration of Cu-Au deposit in Xunhua of Qinghai, which is covered by heavy quaternary. In Qinghai grassland which is covered by quaternary on the surface, induced polarization method has irreplaceable superiority than the other methods in terms of discovering metal sulfide ore body, and the results can be achieved in prospection if proper devices and measuring parameters are used.