Development of genetic collection is considered to be an essential part of genetic resources of cultivated sunflower. The VNIIMK genetic collection of identified alleles determining oleic acid content in the seed oil consists of about 50 constant inbred lines. Fourteen of them are in a core collection. The general range of this trait varies from 20 to 92%. These inbred lines correspond to four main phenotypic classes: low conventional mid and high oleic. The normal line RIL100 was shown to contain a high oleic mutation Ol in hypostatic condition. The mid oleic LG27 averagely 67% does not contain the high oleic mutation in genetic background. The high oleic LG 26 with relatively low content of oleic acid about 86% possesses resistance to suppressor's actions.