Changes in the urban spatial structure originate from a variety of factors that one of them is urbanization. Urbanization is measurable with two categories of population and employment. The population is not distributed uniformly in the city; but depending on the circumstances follows different patterns. Also, the factor of the population, along with other spatial parameters, is the source of the creation of secondary nuclei and also affects the spatial distribution of employment. In this research, the main goal of the study is to investigate demographic changes and activity centers as spatial distribution in Ardabil. In this research, with quantitative, descriptive and analytical methods, the spatial patterns process of population and employment patterns have been investigated. The data used for demographic analysis were census data from 1390 and 1395. But for the study of the spatial distribution of employment, were used from data commercial and service uses for the years 1385 and 1390 the comprehensive plan of the city of Ardabil. The data analysis method is the general and local Moran. The results indicate that the population of Ardabil city during the years of 2011 and 2016 follows the cluster spatial pattern that this process has increased over time. Also, the spatial distribution of employment is clustered with sub-centers; therefore, can be concluded that the urban spatial structure has been moving towards polycentric becoming in recent years.