Abstract：When a point current source is located at any position in a borehole,two-region boundary problem of solving for Poisson's equation in the boxehole and the formation cam be cnanged into three-region boundary problem of solving for Laplace equation in the cylinder whose radius is smaller than the distance between source and borehole axis，in the hollow cylinder between source and well wall，and in the fororation. The}contribution of current source is embodied on the boundary condition of cylindrical surface in which the source exists,and eccentric Green's function of potential can be obtained herewith. The total potential that is generated by eccentric dual laterolog tool in the horizontal well may be derived from the integration of eccentric Green’s function along electrode system，so that apparent resistivity response can be calculated finally. Some eccentric borehole correction charts for deep and shallow dual laterologs are drawn according to the calculated data.
