This contribution is focused on the kinetic and causal correlations between production of intercellular signalling molecules and biochemical events in the regenerating liver after partial hepatectomy. The events of individual cell cycles, particularly their DNA synthesis, are used as the reliable time-markers of regenerating process. The signalling molecules produced in regenerating liver are represented by cytokines, derivatives of arachidonic acid and inorganic molecules as nitric oxide. They regulate the functional activity of each other and form the common system of intrahepatic communication. Particular sets of acting signalling molecules are typical for the different phases of liver regeneration. The liver transit from the relative quiescence to the proliferation and the initial proliferative response of the hepatocytes are predominantly regulated by the signalling molecules produced by the sinusoidal cells. The proliferation of sinusoidal cells themselves is characterized by reduced paracrine activity. Thus the proliferative activity of one type of liver cells synergize with the cell specific activity of other cells, thereby providing cell-specific mitogens, while the proliferative activity and cell-specific in each type of cells antagonize. It appears that for each type of liver cell's, specific mitogens are required that suppress the DNA synthesis in the other cells of the liver.