A group of well-defined exciton transitions from the localized states were observed inZnSe-Zn0.75Cd0.25Sedouble-superlattice structure. The photoluminescence and photoreflectance have been employed to study the subband transitions at low temperatures. At 1.4 K, except the two ground states and two higher subbands ofn=1light-hole andn=2heavy-hole excitonic transitions, other four peaks (A, B, C, and D) also were observed in wider-well superlattice. Those peaks were attributed to the excitonic transitions fromn=2heavy-hole subband due to the fluctuation of well-barrier interface. Another localized excitonic transition from narrower-well superlattice appeared as increasing the modulated intensity in photoreflectance spectra. ©1998 American Institute of Physics.