Foliar fertilization differentiated the essential chemical composition of spring rape seeds to a small degree. Agrosol R significantly reduced fibre content as compared to Ekolist Standard and objects without fertilization. The relative content of ash was significantly higher after top dressing with Agrosol R after application. The productivity of fat and protein was considerable differentiated in reply to fertilizers. After Mikrosol R, applicate on fat productivity was significantly higher than after application of Agrosol R, Plonvit R or in objects without a fertilization. Higher productivity of crude protein was observed in rape, with Aerosol R, Plonvit R and Ekolist Standard application than in control. The cultivars investigated were characterized by similar productivity of fat and protein, but had essential chemical seed composition differentiated.