Abstract: In this paper, a new mathematical form, matrix, continued fraction (MCF) is introduced to describe the decay of effects of an equilibrant system of forces acting on a sphere of an elastic body.By this way, the famous Saint-Venant's principle is proved often but not always valid in computational mechanics.

Key words: matrix continued fraction, static decay, Saint-Venant’s principle, matrix structural analysis, substructure, superelement, chain model