The transmission of DC electric fields by thunderclouds with charge distributions is investigated analytically for the region between the ionosphere and the Earth surface. In such a way the hitherto existing presentations of thunderclouds by electric charge centers (monopole presentation) are generalized to much more adequate three-dimensional model charge regions. A modified ellipsoidal Gaussian profile for the charge distribution of the electrified cloud is accepted. The electrical conductivities are approximated by piecewise exponential functions of altitude. An assumption is made that the geomagnetic fields lines in the lower and middle atmosphere are straight and vertical. Analytical solutions to Maxwell equations for the electric potential U and field E are obtained. The effect of the spatial distribution of the charge on E is investigated. The variations of the electric fields at the ionospheric and surface levels, which are caused by different charge distributions, horizontal sizes, and heights of the electrified clouds, are analyzed. ¿ American Geophysical Union 1994