The concentration of total Protein during the metamorphosis of the cabbage worm, Pieris rapae Linne were measured using micro-kjeldahl method. Healthy specimens were chosen as samples of each developmental stages: the final instar larva, the newly molted pupa, pupa 2, 4, 6, 8, 10 days, newly emerged adult and adult 2 days. The total protein concentrations decreased gradually until the 4 day pupa and increased at 6 day pupal stage and newly emerged adult and adult 2 day stage they were increased again. Hence, changes in tatol protein concentration 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.