The concentration of total protein during the metamorphosis of the Indian meal moth, Plodia interpunctella $Hddot{u}bner$ was measured using micro-Kjeldahl method by Oser(1965). Healthy specimens were chosen as samples at each developmental stages: the 1st instar larva, the 3rd inster larva, final instar larva, pupae 2, 6, 10 days and the adult 1 day. The total protein concentration decreased gradually until the two day pupal stage and increased at the six day pupal stage. In the one day dault stage, the concentration reached a maximum. In conclusion, changes of total protein concentation through the course of the physiological cycle form a U-shaped curve when graphed against the histolysis of larval organs and the histogenesis of adult organs. In view of controlling pest, the U-shaped pattern of physiological activity indicates that control will be the most effective at the time of the most physiological weakness manifested at the two day pupal stage.