The purpose of this paper is to examine the impact of urban spatial evolution of the modern attitude that has to do with a case study Ahar. based on the structure of Iranian cities including the cultural heritage of this land are severely threatened today because modern attitudes have been found and destroyed.The overall research model cities during the two periods, Islamic and modern outlook and match it with Ahar, research methods, descriptive, analytical and comparative degree and the quality is done, the result was that the effect of exogenous influences on the development of vision-based Muslim Ahar, the configuration of the constituent elements of the original and of course, the market as the backbone of the city's mosque, Ark state and localities in which the organic link interconnect structure have been in continuous, systematic and coherent structure and changing the layout of your lost cities of the "market" in Islamic thought "Street" in modern thought, has caused the town through the body, causing a rupture, a major transformation and cause tissue to be worn.