The exciton levels in ZnSe/ZnS superlattice is studied theoretically and experimentally for the first time. The energy levels of electrons, holes and excitens in the superlattice as a function of barrier width are calculated with LCAO theory and Kronig-Penney model. The absorption and photoluminescence spectra of a sample with a barrier width of 5.8nm are measured at 77K. The experiment results are in good agreement with the theoretical calculations.