The dissertation summarizes the current state of breeding achievements in Ukraine and the world in field of improving the maize grain biochemical components, presents the results of research on the selection source material for creating maize hybrids which will combine high level of protein, starch, oil in grains and high yields. Аnalyzes the scientific work of domestic and foreign scientists-breeders. The indicators according to which the source material for hybrids creation with the set quality parameters is selected are generalized. It is determined that effective heterosis selection is possible only with a detailed researching parent components on a set of valuable features. Аnalyzes the soil and climatic conditions of the research site, identifies the research material, describes the main methods. Mathematical and statistical methods of processing the obtained data are also briefly described. Рresents the results of 65 experimental maize hybrids evaluation which created on basis of collected inbred lines collection. Hybrids were evaluated by contents protein, starch and oil in grain and yields. The inbred lines VK13, VK69, AE392 and AE801 were chosen as maternal forms for carrying out tester crosses. Lines characterized by high, stable over the years, constants of specific combining ability. As a result of the obtained data analysis, the following hybrid combinations were distinguished within their groups: with high protein content: VK13xCO255 – 13,07 %, VK13xVK37 – 12,60 %, AE801xAE746 – 11,27 %, AE801xFV243 – 11,18 %; with high starch content: VK13xUHK678 – 72,60 %, VK13xUHK686 – 72,57 %, VK69xFV243 – 72,80 %, AE801xVK32 – 70,83 %; with high oil content: VK13xUHK686 – 5,07 %, VK13xVK37 – 5,27 %, VK69xVK13 – 5,27 %, AE801xAE746 – 5,13 %, AE392xHLG1203 – 5,83 %. Hybrids VK69xG255 and AE801xVK13 were characterized by a high level of yield. The data on the indices of growing conditions were obtained, so the experimental fields of the National Agricultural Research Service of Ukraine are characterized by the best conditions (Ij=0,38). The hybrids AE801xVK13 (bi=3,6) and VK13xAK159 (bi=5,9) are the most suitable for intensive cultivation. The results of the determination of ecological stability indicate that the hybrids VK13xNP2143 (σd^2=0,01), AE801xVK69 (σd^2=0,14), VK13xFV243 (σd^2=0,21) are characterized by the best indicators. Correlation coefficients of each grain quality indicator with grain yield were determined separately for each group of hybrids. It was determined that the highest, stable over the years effects of the manifestation of true heterosis in starch grain content were noted in hybrids VK13xUHK678, VK13xUHK686 and VK69xFV243; by oil content - VK13xUHK678, VK13xUHK686, VK13xVK37, AE392xHLG1203, AE392xCO255, AE392xAK157; in terms of productivity, the most significant values of true heterosis (> 100%) were recorded in hybrids VK13xUHK686, VK69xG255 and AE801xVK13. It is established that the character of inheritance and the degree of manifestation of phenotypic traits and quantitative indicators of the main biochemical components content in grains, as well as the level of yields is directly dependent on the maternal component of the hybrid.
