one way to study the historical development of architectural styles from a structuralist perspective is to study the theories that have explored this category in relation to living structures. These theories, since they are based on the assumption that the inherent quality of living structures are positively influenced by human perceptions, provide a good basis for such studies. In this case, it is possible to examine the history of architectural structures within the framework of their adaptability to concepts such as immortality, vitality and the fulfillment of human expectations of architecture. Also suitable conditions for stylistics and examination of the evolution of styles are provided without regard to all factors affecting the architecture except its structure. The theory of the characteristics of living structures by Salingros (2006) is one of these theories that, based on comparative studies, extends the thermodynamic rules governing natural structures to architectural structures. Therefore, the purpose of the present study is to investigate the evolution of Iranian architectural styles based on Salingrus theory in order to present the evolutionary history of the building from this point of view of the life of the building. For this purpose, samples selected from the list of important Iranian architectures, listed in the UNESCO World Heritage List and Iranian Cultural Heritage list and based on the views of artistic representatives suitable for Iranian architecture. Therefore, with a structuralist approach and by means of a comparative method, these samples were structured and based on the data obtained, their course of change and development took place within a given time. Study of this shows that Iranian architectural styles in the Khorasani, Razi, and Tehranian styles in the post-Islamic period have been declining in terms of life structure and development compared to other styles. It seems that this decline is mainly due to simplification in the design of structures, and its rate is lower than that of the modern architectural era in the course of west architectural development.