The purpose of this study is to observe the movements of Five Mimic-Animal Boxing(FAB) by the "three barrier in the back" of Donguibogam. The subject of this study is observation of the movements of FAB according to practice. The term of training FAB is two years and six months. By the theory of "three barrier in the back" in Donguibogam, we analyzed the movements of FAB. The standard of judgement was the union of the basic point in the arm and leg & the action point in three barrier in the back. The study results were as follows. The movements of FAB operated on the three barrier in the back. The preliminary exercise operated on one, two, trree barrier in the back. And moreover the remainder exercise operated on one, two, trree barrier in the back. The movements of FAB operated on the three barrier in the back for the circulation of vital essence and energy. FAB is the very important Gigong exercise on opening the three barrier in the back.