Abstract: In the conventional electrical logging,the apparent resistivity of wall rock is calculated by the electric current and the potential difference between electrodes.As the same time,the stratigraphic interfaces are divided by the apparent resistivity.However,the current parameter is often ignored.In this paper,we could get the resistance change of the wall rock by the change of the electric current based on the ohm's law.And then we identify the stratigraphic properties by the current intensity curve.Theory analysis and experiment show that the current of the electrode depends on its contact resistance,but the apparent resistivity depends on the sizes of the two receiving electrodes or the electric array,that is the integrated result.So the sensitivity of current logging curve is higher than the apparent resistivity's.The layer interface can be accurately divided with the current intensity of logging curve and the thickness of strata is determined.It is attractive because almost free cost.