This study was conducted to investigate the life cycle of Kunugia yamadai Nagano attacking Qriercrrs spp. in Chungju area, Korea during 1987-1989. The moth had one generation a year. Host plants of the species were Quercus acutissima, Q. serrata, Q. aliena, and Castanea crenata. And Q. dentata T., and Q variahilis B. were newly recognized as host plants of the insect. Young larvae were hatched from the overwintered eggs and fed on the leaves from late April to early August which took ahout 3 months. In mid-August, the fully grown larva made a rough cocoon and pupated at the ground debris or dense grass. The moths emerged from September to late October with a peak around mid-October. Female oviposited 121 eggs on average mostly on the bark of host plants at 131 cm ahove the ground.