The structure of doctrines, or religious dogmas, consists of some general notions set in a special way, used to refer to the body of Islamic fundamental beliefs. Muslim theologians have considered the structure of Islamic doctrines along with their content. This has been articulated in different ways. They have, sometimes, explicitly referred to a certain structure and even have justified it; and sometimes, they have merely used the books on structural doctrines for classifying their materials. The present article uses a typological perspective to investigate the views of Imamiya scholars on the structures of Islamic doctrines on a historical basis and show that those scholars, in the Occultation Period, have presented Islamic doctrines in five different structures as follows: (1) Dual structure (monotheism, justice); (2) Four-part structures type I (monotheism, justice, prophethood, imamate); (3) Four-part structures type II (monotheism, prophethood, imamate, resurrection); and (4) Five-part structure (monotheism, justice, prophethood, imamate, resurrection). In the present article, the turning points where various structures were rivaling one another, or turned into one another, are investigated.