Abstract: Based on the calculations and analysis of numerical simulation, this study result shows that the amplitude of geoelectrical field originated from natural source (magnetosphere, ionosphere) increases with the increase of frequency. For the same frequency, the higher the resistivity is, and for the half-space geoelectrical structure, the larger the amplitude is. When the resistivity of the overburden layers in two layered medium is the same as that of the former structure, the higher the resistivity of the second layer is, the larger the amplitude is than that of the half-space geoelectrical structure. When there is the third layered medium with high resistivity under the second layer, the amplitude of the geoelectrical field is larger than that of two types of situation mentioned above. When there is an inhomogeneous body in half-space medium, the higher the resistivity of the inhomogeneous body is, the larger the positive polarization is, while the lower the resistivity is, the magnitude of the geoelectrical field is.

Key words: Geoelectrical field, Natural source, Geoelectrical structure