In regional gravity measurement of mountain areas, the area selected for topographic correction should be somewhat large so that the influence of to pographic relief might be eliminated to a satisfactory extent. When studying topography of the distant area and the stone-slab effect, one should take into account the crustal curvature. Therefore, in distant area correction, the sphe rical surface passing through the survey point, rather than the plane surface, should be adopted as the reference. As a result, negative topographic correc tion value may occur. In stone slab correction, the influence of the curved disc whose radius is consistent with the maximum radius of the topographic correction ought to be eliminated. This influence is related not only to the radius, but also to the thickness of the curved disc.In this paper, a set of theoretical calculations for different radii and thi cknesses of curved discs are given. With these calculations, the stone slab cor rection formulae corresponding to different correction radii are obtained, whi ch can be consulted directly.