Gagarina, Troitsk, Chelyabinskaya Province, 457100 Russia, e-mail derkho2010@yandex.ru A b str a c t Individual growth and development is a gradual vector process. <...> Each period of ontogenesis is characterized by certain morphological and functional changes in organs, systems and the organism as a whole. <...> Organic and functional transformations are genetically based and realized in the course of adaptation to the external environment factors. <...> The transformations occur at different levels of which the intracellular level is the basic one. <...> As far as biosynthetic processes and circulation of metabolites are separated, an occurrence of some elements for their regulation seems to be possible. <...> For instance, structural cell components probably can be most effective regulators due to ability to contribute to morphological and functional integrity in cell. <...> Membranecell response is a key element of molecular regulation. <...> Phospholipids, the main components of cell membrane, are extremely sensitive to external and internal factors, being at the same time relatively stable due to genotype effect and adaptation ability. <...> Participation and the role of subclasses of phospholipids in the functions of broiler chicks are little known. <...> In this regard we have carried out the study of phospholipids profile of ISA-15 Hubbard F15 chicks during ontogenesis, particularly in eggs before and on day 10 of incubation, and in blood serum of chicks at postnatal period on days 1, 7, 23 and 42. <...> The experimental chicks were kept at a poultry farm in Chelyabinsk Province. <...> To establish the functional groups of subclasses of phospholipids in the ontogeny of broilers we used the multivariate cluster analysis. <...> It was shown that in egg before incubation the phospholipids were grouped into two separate clusters (phosphatidylcholines and cerebrosides, Euclidean distance 1.08; and phosphatidylethanolamines, Euclidean distance 1.61) and one joint cluster (phosphatidylinositols with sphingomyelin and lysolecithin with cardiolipin, the Euclidean distance of 0.23). <...> On the day 10 of incubation there were two joint clusters (lecithins with cephalins, the Euclidean distance of 1.61; phosphatidylinositols, sphingomyelins, cerebrosides and lysolecithin, Euclidean distance of 2.06) and also a transitional group (cardiolipins). <...> During postnatal ontogenesis in 1-day old chickens three groups of phospholipids were found (lecithins, the Euclidean distance of 2.07; phosphatidylethanolamine with the cardiolipin, the Euclidean distance of 0.26; lysolecithin), while in 7-day old chicks there were two combined clusters <...>