CdSe/Cd0.8Zn0.2 Se quantum wells were grown by means of molecular beam epitaxy on substrate GaAs. The emission peak from excition-exciton scattering is observed in CdSe/CdMnSe quantum wells. When weaker excitation is used, radiative recombination decay time of the exciton is reduced as the excitation intensity is decreased. The results indicate that the dominant mechanism may be quenching of exciton emission by impurities and defects.