Abstract: The article studies urban censuses taken in Moscow and Saint Petersburg at the turn of the 20th century as important sources for labor history studies (a cross-disciplinary field of research). The article addresses aggregated data of urban censuses taken in Saint Petersburg in 1881, 1890, 1900 and 1910 and in Moscow in 1882, 1902 and 1912 which provide occupational data. The research subject is the structural content of census occupational tables. When analyzing Moscow and Saint Petersburg censuses, the comparative-historical method is used to identify similar and unique data of historical sources. Despite numerous studies carried out by Russian and foreign scholars addressing pre-revolutionary censuses, one of the aspects of the sources (that is temporal occupational distribution of males and females in Moscow and Saint Petersburg) is still poorly studied. The article briefly describes the creation of each census, analyzes the way occupational data were registered and shows changes in the census program of Saint Petersburg and Moscow from 1881 to 1912. One can see different formation of Moscow occupational groups. Whereas an industry branch prevailed in 1882, social status of the worker dominated 1902 and 1912 censuses. In Saint Petersburg the distribution was related to an industry branch accompanied by a production status. The author considers census structure studies important for comparing temporal data and further analysis of labor activity in Moscow and Saint Petersburg presented in the sources understudy.