Sunflower seeds accumulate significant amounts of storage proteins nging to the two major classes, the 11S globulin (helianthinin) and 2S albumins. The 2Salbumins are sulfur-rich water-soluble low molecular weight single-chain proteins with a molecular weight approximately 12-15 kDa. The major component of sunflower albumin fraction is the unique SFA8 protein. It consists of 103 amino acids, includes 16 methionine residues and constitutes up to 7% of total seed protein fraction. The level of SFA8 in seeds of individual genotypes can exceed 7%. Because of lipid affinity the SFA8 protein possesses a high emulsifying ability. The possibilities of using the SFA8 protein as a source of essential amino acids are limited by its high allergenic properties due to presence in the molecule of conserve IgE binding epitopes. The level of SFA8 varied among the sunflower lines and significantly increased in the F1 hybrids. The SFA8 electrophoretic variant called SFA8v was found in five lines of sunflower genetic collection. The SFA8v polypeptide differs from the “wild” type protein SFA8n by electrophoretic mobility in polyacrylamide gel (tris-tricine electrophoretic system, pH8.8) and isoelectric point (pI 5.87 and 6.36 correspondingly). It was shown by classical hybridological analysis that the SFA8 polymorphic variants are coded by the allelic genes. For elucidating the molecular basis of the polymorphism observed the 792857 bp genomic fragments representing most part of the SFA8 locus from different sunflower genotypes were cloned and sequenced. The cloned SFA8 genomic fragments included the intron of 250-300 bp lengh in the central part of the gene. The intron was polymorphic and characterized by the presence of 45-50 bp indels among the cultivated and wild Helianthus species. The SFA8 coding sequences and in silico translated amino acid sequences were polymorphic in the studied genotypes. In the line VIR130 expressing variant SFA8 protein the substitution C-G in position 108 was found which resulted in substitution of serine for arginine. Such a substitution leads to changing isoelectric point from 5.87 to 6.36 and also can alter protein charge and mobility in the polyacrylamide gel. Amino acid polymorphism of SFA8 polypeptides including variation in the number of methionine residues in different genotypes was also predicted. According to results of bioinformatic analysis the SFA8 isoelectric point constituted 5.16-6.36 in different H. annuus lines, the charge varied in the range between ˗0.715 and ˗2.805, and the calculated GRAVY (grand average of hydropathy) index was from ˗0,541 to ˗0,622. The number of trypsin cleavage sites was different in various genotypes that can condition variability of protein allergenic properties.