Utopian thoughts have precedence as old as human history. Islamic civilization utopian thought owes its progress to the Farabi&rsquos utopian concept and expansion and academic study of utopian term in west owes to the Thomas More Utopia book. Theoretically, Farabi&rsquos utopian thoughts influenced development of utopian system in both Islam and Western civilizations. By emphasis on Farabi&rsquos Utopia as an example of utopian ideas in Islamic civilization, and Thomas More&rsquos Utopia as an example of utopian though in the western civilization, this research tries to investigate the commonalties and differences of these utopias. The architectural and urban building spaces of these examples were studied in the conceptual viewpoint. Thomas More Utopia consists of fifty four similar cities. All of the cities have been constructed well according to the same plan as possible as. The nearest cities have approximately twenty four miles distance, and the furthest ones are not so far from each other so that the people can travel less than one day. Because of similarities in the cities, only one of them has been referred in the &ldquoUtopia&rdquo this city is Amaurot. Each city sends three wise old men to Amaurot every year to negotiate on their common affairs. Amaurot is the main city of the island and it is near the center of the island. &ldquoThe opinions of the Utopians&rdquo and &ldquoThe Policy of the City&rdquo are two books of Farabi. He expresses the political and philosophical systems of Utopia comprehensively. He divides communities qualitatively and in addition, there are cities in contrary to Utopia. He pays attention to the quality of communities from perfectionism and auspicious perspective. In other words, the goal of the city determines type of the city. Farabi likens utopia to a creature that has independent existence beyond the members of the city.� The comparison of the architectural and urban building spaces of Farabi&rsquos utopia and Thomas More&rsquos utopia showed that both of the cities are placed in the defined space from urban structure perspective both of them have defined volume and level, and the difference is that Thomas More&rsquos utopia is located in an islands and Farabi&rsquos utopia is universal. The More&rsquos city has a defied localization but Farabi&rsquos city does not posse this characteristic. Farabi has referred to the market space and transaction regarding to the urban micro spaces while Thomas More has referred to passages, hospitals, market and hall and other specification, situations and services. More has not explained the social and geographical divisions, but Farabi divides his utopia into complete and incompetent city and offers subcategories of human communities. Thomas More has emphasized on the urban divisions on streets and fragmentation of the city and also has referred to details like type of material, material used and entrance of city while, in Farabi&rsquos utopia has no references to the details of� the architectural spaces and he has emphasized on educational and social goals.