Silage maize as a fodder crop has been still produced in Republic of Serbia at insufficient surfaces, mostly at holdings focused to livestock production, providing on that way adequate volume of quality animal feed. In order to determine economic effects of production in paper is used analytical calculation based on variable costs, as well as method of critical values of production and sensitive analysis. Analysis covers three year period, involving comparison of gained results. Paper goal is to present the results achieved in mentioned production, as to evaluate the importance of yields height to gained contribution margin (positive contribution margin was determined within the complete period).