The pre-Islamic styles of Iranian architecture draw on 3-4 thousand years of architectural development from various. Each of the periods of Elamites, Achaemenids, Parthians, and Sassanids were creators of great architecture that over the ages has spread wide and far to other cultures being adopted. Although Iran has suffered its share of destruction, including Alexander the Great's decision to burn Persepolis, there are sufficient remains to form a picture of its classical architecture. This paper featuring a chronological description of structural styles, information on traditional construction materials, as well as an analysis of numerous structures, this interest and informative text will be of importance to anyone with a technical interest in structural history and presents a general overview of the structural and architectural characteristics of Iranian historical structures and investigates historical buildings of Iran through a structural engineering approach. This paper includes a chronological description of architectural styles from the beginning to the end of Sassanid’s (before Islam).