In the period of economic transformation, economic changes in Poland contributed to changes in the structure of employment. Many institutions and factories closed, production profiles and ownership forms changed, new technologies were introduced, and, as the result of all those factors, labor force decreased in industry and in building industry. The character and scope of the phenomenon was analyzed in this paper, based on the data from a number of cities, where, after 1992, the population was 100,000 or more. Forty two cities were included in the research (data from smaller cities aren't available). Positive input data were collected in 1992 and 2001. Based on research data, participation of employed people (in %) in groups of working age people was established in three categories: industrial and construction workers, employees in other areas of employment, unemployed. The categories were used in order to analyze the situation in different periods of time, to compare the results, and to analyze the changes, which occurred in different periods. In general, time of self-correlation was analyzed in reference to each category of employed and unemployed people. Also, the analysis included the correlation between the range of changes in the percentage of industry and construction workers, the range of changes in the percentage of people employed in other sectors, and the percentage of unemployed people. In particular, the structure of changes was analyzed in reference to the participation of industry and construction workers, and in other employment sectors, and the participation of unemployed people in reference to input data (1992, see charts). Typological groups were established for different cities in connection with the character of changes in a researched time period. Functional classification was established for different cities. (original abstract)