Abstract: With geology exploration complicated,electromagnetic instruments generally used should be of themselves features for different objects,aim and requirement,which is adaptive to the trend of specialization of electric products recently.Furthermore,this is realistic need in practice.This paper puts forward special demands on high-powered,high sampling frequency for TEM and high density frequency and multi-station for CSAMT in accordance with character,electric feature of strata and prospecting task of coalfield exploration,specially with hydro-geological exploration of Northern China type coal field.