Abstract: In this article, the energy-level splittings of a multi-layer supperlattioe are analysed theoretically and a simple expression about the splittings has thus been derived. It is clear to see that the energy-level of a single well splits into a number of levels as a result of the coupling of the wells, the number of the splittings being just the same as expected as that of wells. The splittings of a certain energy level are not only related to the energy level but also relevant to the material parameter and structure parameter of the super lattice. The result has been applied to a GaAs-Alx Ga (1-x) As superlattice, and the calculation about its energy-level splittings yields data in pretty good agreement with experimental values.