A recurrence method for analytical and numerical evaluation of tunneling, transmission, and re6ection amplitudes is developed. As the 6rst step, a rule for composition of two arbitrary scatterers separated by a region of constant potential is obtained. Transmission and re8ection amplitudes for this double-barrier potential are expressed in terms of transmission and re6ection amplitudes for its subparts. As the length of the constant-potential region can be arbitrary and the subparts of a potential may, in turn, be arbitrary segmented potentials, one obtains recurrence formulas which express the scattering amplitudes for the arbitrary segmented potential via the scattering amplitudes for the subparts into which the complete potential can be divided. The efBciency of the method is demonstrated by solving analytically the problem of scattering from locally periodic potentials. Since an arbitrary potential can be approximated by a set of infinitely narrow rectangular barriers, the recurrence formulas can be applied to any potential, giving, in the limit of zero-width segments, difFerential equations for transmission, and reffection amplitudes.