Problem Statement: Russo-Persian Wars were one of the important factors in understanding the modern world by Iranian. Moreover, trips that made by officials to Russia, due to historical and political events after the war, were the main factors in encountering the new world and modernity. Therefore, along with long-standing interactions with Russia, and neighbor neighbor countries in various fields, it seems that by concluding numerous contracts, in addition to the increasing presence of the Russians in Iran (especially in the northern regions) and the construction of various buildings with the architectural knowledge of that time of Russia (neoclassical architecture), the Iranian proprietors have also constructed monuments with an inspirational Russian style in Iran, by observing the neoclassical structures of Russia, in order to demonstrate the power of their own government. Purpose: In this regard, the purpose of this study is to examine the role of Russia on using European architecture and western architectural elements in Iran and identify the patterns of Russian neoclassical architecture and retrieve them in the administrative-service buildings of Iran. Methodology: This is a comparative-qualitative research which uses library, documentary and field studies. Historical-interpretive research method has been used to collect historical theoretical bases and descriptive-analytical research method has been used in the field of architecture. Conclusion: The results of the research showed that Russia played a very important role in the entry of western architectural elements into Iran during three stages of «understanding», «observation» and «implementation». Patterns were effective in all three areas of the plan, the volume, and the faç ade of buildings. Emergence of objective components was more significant than other two components. The most commonly used architectural parameters of this style in Iran› s administrative-service buildings include: the long hallway with numerous rooms around it, the gable roof, the balcony, semicircular and long narrow rectangular windows, and balustrades.