The main subject of theoretical-empirical study presented in this paper is the estimate of the relationship between changes in the value and structure of equity and profitability of the enterprises listed on the Polish and German capital market. For the purposes of achieving the work formulates the main research hypothesis, stating that to increase the profitability of public companies is associated with significant changes in the value and structure of the equity. The discussed research problem was investigated in the form of a comparative analysis and realized in two parts. The discussion presented in the first part depicts mainly theoretical deliberations upon the role and meaning of the structures of equity in the joint-stock companies....