Abstract : This study submits to our attention some qualitative and quantitative aspects related to urban and semi urban habitat from the former Arad County in the eighteenth century. If in 1715 there were 6 market towns, at the end of the century were already 15. Based on the conscriptions, urbariums and census, I have tried to detect the evolution of market towns during the entire eighteenth century. Reform policy of the Habsburg absolutism has determined even an economic and demographic increase in the market towns of Arad County. Between those 15 market towns of the county existing in 1787 only Arad had obvious urban characteristics. Here was concentrated 6.15% of the county population. By comparison with other counties from Transylvania and Hungary, I have pursued to dignify and quantify different aspects of the urbanization degree in the Arad County registered in the eighteenth century. The development of market towns in Arad County has had the same evolution with those of Central and Eastern Europe, because the agrarian character of these localities was predominant. The evolution towards urbanization was evident along the eighteenth century both in terms of population growth and a great social mobility and also in light of the economic and municipal development. The transformations in the direction of modernization registered during the eighteenth century were the basement of the future process of urbanization of Arad County in the century that has followed.