At low temperature, ZnSe emits strongly the near-band-edge luminescence consisting of the excitonic emissions and defect-related ones. However, it was observed that these emission lines are strongly fatigued under ultraviolet irradiation. Based on various experiments, we propose a mechanism of photo-induced traps to explain the photoluminescence fatigue phenomenon. These traps are created or enhanced in ZnSe by irradiation of the ultraviolet light with photon energy much above the band gap energy of cubic ZnSe,