National censuses provide us with a variety of statistics that can be used in sociological studies. This study attempts to analyze the structure and changes of Iran's social stratification on the basis of "job status" and "major occupational group" tables in national census publications from 1956 to 1996. In this study, after a review of the present literature on the theories of social stratification, a theoretical framework is suggested which presents Iran's social space on the basis of three dimensions: economic capital, socio-cultural capital, and political capital. Social agents occupy a place in this space based on the total amount of the aforementioned capitals. The groups which have similar situations in this space constitute a social stratum. By combining the previously mentioned tables and using the characteristics of this social atmosphere, high, traditional middle, new middle, and low strata, as well as the proportion of each one in the total number of occupied people, were identified. The comparison of results showed that extraordinary quantitative and qualitative changes have happened in the period under study.