Urbanization has been a major factor of natural resource degradation in the Semirom region of Isfahan province. This study aimed to evaluate the impact of urban development through land cover/ land use changes over a 37 years period using Landsat 1976 MSS and 2013 TM images and population data. First, necessary processing (geometric, radiometric, topographic) was applied on images. Then by using field assessment and GoogleEarth software, sample points were selected. The land use/ cover maps of the region and their changes were extracted by maximum likelihood classifier and post classification methods and their accuracy were assessed through overall accuracy and Kappa statistics. The accuracy assessment showed that the accuracy of maps in 1976 and 2013 was about (overall accuracy) 80 and 92%, respectively. The population was increased during three decades from 41973 to 65047 persons which has led to an increase of 0.90, 0.26 in the urban and agriculture area and also a 3 percent decrease of rangeland area. The 2.5 fold increase in bare land area in 2013 in comparison with 1976 indicated the severity of land degradation in the study area. Overall, drought and urban area attractions have facilitated the migration of people from villages to the city and had considerable negative effects in natural resources. Therefore the region requires a holistic approach in all economic, social and environmental developments.