A new theory of gravitational field representation is created to unify the exterior andinterior disturbing fields of the earth by using Newton’s potential operator. To do that wego this way: first, we analyze the invertibility of Newton’s potential operator and come tothe conclusion that every continuous function belonging to D_g, the orthogonal complement tothe null space of this operator, is harmonic everywhere in the interior earth space; second,we formulate a new kind of boundary value problem of gravics-interior Dirichlet’s prob-lem of biharmonic equation with respect to disturbing potential on the supposition that anom-alous mass density of the earth belongs to D_g; then, we simplify the disturbing field intoa quasilinear superposition of two harmonic fields by the aid of the representation theoremson biharmonics proved in this paper. In this way, we finally end up with a unified represen-tation pattern AL of disturbing potential defined throughout the whole space, where L de-notes data performed A new theory of gravitational field representation is created to unify the exterior and interior disturbing fields of the earth by using Newton’s potential operator. To do that wego here way: first, we analyze the invertibility of Newton’s potential operator and come tothe conclusion that every continuous function belonging to D_g, the orthogonal complement tothe null space of this operator, is harmonic everywhere in the interior earth space; second, we formulate a new kind of boundary value problem of gravics-interior Dirichlet’s prob-lem of biharmonic equation with respect to disturbing potential on the supposition that anom-alous mass density of the earth belongs to D_g; then, we simplify the disturbing field intoa quasilinear superposition of two harmonic fields by the aid of the representation theoremson biharmonics proved in this paper. In this way, we finally end up with a unified represen-tation pattern AL of disturbing potential defined throughout the whole space, where L de-not es data performed