The article presents a study which examines the effect of Lipopolysaccharide's (LPS) structure on the activity of the blood lymphocytes of human during cell activation early stages. The study uses nontoxic LPS from Rhodobacter capsulatus, toxic LPS from Salmonella typhimurium, and healthy peripheral blood with heparin. Results show that the changes in the synthetic apparatus of lymphocytes can be recorded and detected at the lymphocytes activation's early stage by lipopolysaccharides.