The objective of this study were to investigate the effects of Se and Vit. E administration at last month or two month before parturition on the reproductive function of dams and developmental ability of calves. On developmental ability of calves obtained afier Se and Vit. E administration at the last month of pregnancing periods, the birth weight were significantly higher in administration groups than in control group(P<0.05). However, the weaning weight, average daily gain and weaning age were not significantly difference in all experimental groups. In the comparision of reproductive function in dams, estrus postpartum was faster in treatment groups than control groups(P>0.05). However, the number of A.1 service fur conception were lower groups injected than control group(P>0.05), there were not significantly differences in all experimental groups. The developmental ability of calves obtained after Se and Vit. E administration at two months before parturition were also examined. The birth weight, weaning weight, average daily gain and weaning age were higher in treatment groups than control group, but there were not significantly differences in all experimental groups. In reproductive function of dams, the days to 1 st estrus postpartum was slightly faster injected groups than control group(P>0.05). Number of A.I. service for conception in each groups were lower in treatment groups than control group.