According to archaeological evidence, with the failure of Sassanid dynasty and beginning of Islamic period, very large part of the decorative elements of Iranian architecture in pre-Islamic era, has been taken to serve and developed in Islamic architecture. In this research, the comparative study conducted to compare the architectural monuments of Iran pre-Islamic and decorative elements in Iran, in the architectural Islamic period to the end of safavid period has been discussed. The Iranian decorators in the middle Islamic period have more emphasis to continue of benefiting of ancient decorative architectural elements in Iran. This research is about the influence of ornaments and decorative elements of Iran pre-Islamic, on the architectural Islamic period. Also, showing the decorative elements in Iran of ancient period and the end of safavid period is the else aim of this research. Offering a vision of the evolution of decorative elements from ancient Iranian architecture to end the Safavid period, is the goals of this research.
Method of this research is comparative study. Since the "comparative study" as the basic method used in most studies related to historical factors, the main part of this research, is analyzed using this method. Iranian decorators in medieval Islamic architecture have been more emphasis and insistence on the continued use of decorative elements in ancient Persia. This influence has appeared on the architecture of Islamic period in the structures with religious nature and is designed in decorative forms.