On the basis of presented data it can be concluded, that in the preclinical stage of atherosclerosis development when macroscopically observable arterial lesions are still undetectable, a complex process of structural-functional changes takes place in the arterial wall. Under modern methods of investigation it was shown that the concept of "pre lipid" stage of atherosclerosis morphogenesis is somewhat conventional. The infiltration of atherogenic lipoproteids in the arterial wall, their modification and interaction with cell elements of vascular wall serve the basis for complex cell reactions directed to adaptation to new conditions and expelling of excessive lipoproteids. The obtained data introduce a new level of knowledge about patho- and morphogenesis of atherosclerosis.