We have discussed theoretically the interface structures of superlattices made of materials with different lattice structures. At first, the ideal matching conditions are obtained for the rigidlattiee model. On the basis of these, we have investigated the regions of parameters, where the practical materials may be fitted into these ideal matching conditions through some elastic strains. As an example, the phase diagrams of the interface structures for fee (111)-bee (110) superlattice have been calculated.