The effects of electron beam irradiation on life stage and reproduction of Spodoptera litura were examined. Eggs, larvae, pupae, and adults were irradiated at target doses of 30, 50, 100, 150, 200, and 250 Gy. When eggs were irradiated with 100 Gy, egg hatching was completely inhibited. When irradiated to the larvae, pupation was inhibited at 100 Gy and larval period was delayed. When irradiated to the pupae, emergence was inhibited at over 100 Gy. When irradiated to the adults, longevity and fecundity did not show any differences. However, egg hatching was significantly decreased at 100 Gy and above. Also, electron beam irradiation was not induced the rapid death of S. litura. Reciprocal crosses between irradiated and unirradiated moths demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in S. litura adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage. The recovery of DNA damage in S. litura adults increased as time passed. but DNA damage hasn’t recovered fully. These results indicate that electron beam irradiation induced abnormal development and reproduction by DNA damage in S. litura. and as time goes by, the DNA damage was decresed.