In this paper,by using the electric potential distribution which is originated from the artificial point current sources in the earth model of two horizontal layers as basic solution,we deduced the boundary integral equations about electric potential with an inhomogeneous conductivity object in the earth.Then we got the electric potential distribution on the ground by solving the integral equations with boundary element method,further,we got the calculating results of apparent resistivity.
That the integration is only done in the boundary planes and the direction of observational line is arbitrary are the specific advantages. Using united-section methed,we calculated the apparent resistivi-ty with an inhomogeneous spherical object in the model of homogeneous half space,the results con-formed to the analytical solutions got by other researchers. Using gradient-section method,we calcu-lated the apparent resistivity with a rectangular inhomogeneous object in the lower layer,the angle be-tween the direction of observational line and the trend of rectangular objct is 45°,the results con-formed to the experimental and theoretic analytical solutions got by other researchers.
Finally,we discussed the applications of this method in the field of the precursors of ground resis-tivity and the electric prospecting.