Abstract: Stokes’ approach is one of the most frequently used approaches for determining the global geoid. However, besides the well-known drawbacks, in Stokes’ approach there still exist theoretical difficulties that are not recognized: in case that the geoid is below the surface of a reference ellipsoid (e.g. the WGS84 ellipsoid), the disturbing potential function is not defined and neither harmonic in the whole region outside the geoid. To take away these difficulties from Stokes’ approach, we choose an inner ellipsoid enclosed by the geoid, with four fundamental parameters, with its center coinciding with that of the WGS84 ellipsoid, and two of which, the geocentric constant and rotation rate, coincide with the corresponding parameters of the WGS84 ellipsoid, and the other two parameters, semi-major axis and flattening, are chosen in such a way that the new normal gravity potential generated by the inner ellipsoid has the constant (the geopotential constant on the geoid) on the surface of the WGS84 ellipsoid. By this new formulation, the disturbing potential function is harmonic in the whole region outside the geoid, and the difficulties existing in the conventional Stokes’ approach vanish.