Distinctly different exciton properties in pseudomorphic and strain relaxed ZnCdSe/ZnSe structures grown on GaAs are demonstrated. For pseudomorphic or partly strained structures temperature stability of photoluminescence depends on the distance from the ZnCdSe quantum well to GaAs/ZnSe interface and less on confinement energies. Densities of two‐dimensional localized states and averaged localization energies, as seen by excitons, are determined from the photoluminescence kinetics measurements. These values are compared with the ones reported for contemporary GaAs/AlGaAs structures. ©1996 American Institute of Physics.