Making the best use of his long-term experience and data found in literature the author has summarized this topic. There are two types of antigens polypeptide and olygosacharide antigens. Control of the former is monogenic one gen - one antigen, while the latter is polygenic due to the complex step-by-step synthesis. There are 25 defined blood group systems. Besides there are antigenic collections as well as low and high frequency antigens. They are expressed in five functional categories on the red cell membrane. According to biochemical structure, ABO system antigens are the wide spread protein-polysaccharide complexes acting as membrane glykoproteins and glykolipids. They appear late in the phylogenetic development, first in anthropoid monkeys and then in humans. Number of antigenic receptor sites is proportional to the level of glycosyl transferase during synthesis. Biological function of blood groups is expressed in the recognition sensibility to disease, possible associations and maintenance of cell integrity. Significance of the investigation is genetic, biological anthropological, forensic and medical.
