The researches were conducted in 2015-2017 with the purpose to study polymorphism of avenin-coding loci and component structure of avenin of cultural types of oats of different groups of ploidy - Avena strigosa Schreb. (2n = 14), Avena abyssinica Hochst. (4n = 28), Avena byzantina C. Koch. (6n = 42) and Avena sativa L. (6n = 42). As a result of identification of alleles of avenin-coding loci of hexaploid types of oats it was established that on Avn A locus A1 option, on Avn B locus - B1 and B4 options, on Avn C locus - C3, C2 and C1 had the greatest frequency of occurrence. Earlier not identified blocks of components of avenin con-trolled by Avn C locus had been revealed. To these blocks the numbers C4 * were assigned, to C6 *, S6a and C6b. During the analysis of component structure of prolamin of studied types 12 proteinaceous fractions meeting in the ranges of samples of three different types were revealed. The role of these components in the formation of blocks of components of avenin was estimated. It was es-tablished that component № 119, general for rang-es of hexaploid and Abyssinian oats, was a part of blocks of components of avenin of C1, C2 and C7. Among the components of prolamin, common for sowing, Byzantine and sandy oats were revealed component No. 51 which is a part of allelic C1 and C2 blocks, component № 62 - in the structure of C4 blocks *, C6 *, C6b and S6a, and also compo-nent № 95 - in the structure of e C3 block. Compo-nent № 38 was a part of B1 block and № 67 - B1, B4 and B5 blocks. In our opinion, the samples of sandy and Abyssinian oats had initial genes con-trolling synthesis of general components for the subsequent formation of hexaploid types genes clusters mentioned above.