Role of acute phase proteins (APP) and mechanisms that regulate their synthesis in the liver are considered. It is known that acute infection, trauma and neoplastic growth cause the acute phase response characterized by a complex of local and systemic reactions of the organism. Production of some acute phase plasma proteins increases (positive APP) while concentration of the others decreases (negative APP). In this review the role of the most important positive APP, such as C-reactive protein, the third component of the complement, alpha 1-antitrypsin, serum amyloid haptoglobin, hemopexin and some others and of negative APP such as albumin, transferrin, apoliprotein A-1 is discussed. Synthesis of APP in hepatocytes is regulated by three main inflammatory cytokines, such as IL-1, IL-6, TNF, produced mainly by immunocompetent cells, and by glucocorticoids. Peculiarities of each cytokine effect, their interaction during APP synthesis as well as their regulation by receptors-antagonists and by autoantibodies are discussed. The data described provide evidence for the close relation which exists between the immune system and the liver and is required to maintain homeostasis.