The effectiveness of the selection of oil flax is largely dependent on the expansion of genetic diversity due to the attraction of hybrid sources of wild species with n = 15, which easily interbreed with cultivated flax, in particular L. angustifolium, L. hispanicum, bienne, L. crepitans. The aim of the work was to establish the inheritance characteristics of interspecific and intraspecific hybrids of the first generation of quantitative traits of plant habit, which are important economic traits for creating valuable source material and using it in breeding programs with oilseed. The material of the study was the interspecific and intraspecific hybrids of the first generation, obtained by crossing two wild annual homostilous species L. angustifolium, L. hispanicum and three samples of cultivated flax M 32/2 (IOC NAAS), L 5 (Czech Republic) according to the full diallel pattern L 6 (India), contrasting in terms of habitus (height, number of stems and lateral shoots). Studies were carried out at the Institute of Oilseed Crops NAAS in 2017-2018. Hybrids were studied in an F1 hybrid nursery in blocks according to the scheme: maternal form – direct and reverse hybrids F1 – paternal form. Structural analysis was carried out on 10 plants of the parent components and on all F1 plants. The nature of inheritance of habit characters in the first generation of hybrids was determined by the degree of dominance (Beil, Atkins 1965). As a result of studies, it was found that in the inheritance of plant height in interspecific hybrids positive overdomination prevailed (in 41,3%); in intraspecific hybrids – intermediate inheritance (in 50,0%). In the inheritance of the number of stems per plant in interspecific hybrids, intermediate inheritance was predominant (in 47,4%); in intraspecific hybrids, 50% had intermediate inheritance and 50% had negative dominance. According to the trait “number of lateral shoots per plant” in interspecific hybrids, intermediate inheritance was predominant (in 41,2%); in intraspecific hybrids, 50% had positive overdomination and 50% had intermediate inheritance. The degree of dominance of the signs of plant habit depended on the conditions of the year, the genetic characteristics of the experimental material, the trait under study, and the type of crossing (interspecific or intraspecific). For high selection efficiency, the nature of inheritance in each case should be taken into account. Hybrid combinations of M 32/2 / L. angustifolium and M 32/2 / L. hispanicum, which showed heterosis during the years of research on the basis of the number of lateral shoots per plant, are valuable for creating varieties of oil flax with large branching.