Flint maize differ essentially from dent maize, which has been classified as a special group with special traits (precocity, low temperature tolerance, grain consistency, photoperiodism, etc.). A disadvantage of this group is the sensitivity to high temperatures and low seed production compared to the dent forms. In the breeding program of flint maize as sources of high productivity severed inbreeds of foreign origin: IK169-3, F564, LO3 and Pi187. Research has begun from a synthetic population with 50% in genotype of 12 original early inbreeds and 50% of LO3, individual selected by phenotype for stalk resistance and precocity. Additional to research program also for initial material served simple and three way hybrids, which contains in pedigree inbred lines IK169-3, F564 and Pi187 with participation of 25-30%. After the self-pollination and phenotyping selection work carried out in the F1 generation, segregating biological samples of the F2 generation was sown approximately 250-500 plants per genotype and finally selecting over 3000 individual samples for S1. From the descendants of the S1 generation, phenotypically appreciated, have been identified 1580 families with valuable breeding characteristics. During rigorous selection in S2-S3 generations sown at higher densities, were identified 140 relatively constant samples. After evaluating the combining ability in S4-S5 generations, 12 inbred lines were transferred to the laboratory's operational collection. All of them have been tested in hybrid combinations at most important agronomical traits. Finally, 6 inbred lines with high performance were found and were included in the hybrid synthetization system. The MKP22 line with 25% of the F564 germplasm quickly loses moisture from the kernels and high pollen productivity. Hybrids with that line have shown high grain productivity and low humidity in grains. The MKP22 is the paternal form of the Bemo203 hybrid registered in the Republic of Belarus since 2014. With high grain yield are shown the MKP20 (25% IK169-3) and MKP19A (25% Pi187), also evidenced by the good quality of the ears. Both of them are components of the maternal form in the threeway hybrid Rosmold159CRf registered in the Russian Federation. The MKP19B has the same genealogy as MKP19A but differs in plant height, lower kernels moister and flowering coincidence between tassel and silk emergency. The MKP21/182 (50% F564 and 25% IK169-3), with high combining ability, is a paternal form of the Rosmold202MRf hybrid listed in the Russian plant varieties catalog. The MKP27 line was created from the synthetic population with the LO3 donor germplasm, which present breeding interest by kernels quality and being used as seed parent in the Alimentar325 hybrid, registered in the Republic of Moldova. Research during several years with Euroflint heterotic group at the Republic of Moldova climate conditions has proved the possibility of improving the grain yield at high plant densities, stalk resistance, tolerance to low temperatures, drought and heat.