The morphological features and dynamics of regeneration of the grafted human liver were studied by using data on 609 needle biopsies obtained for morphological monitoring in 38 recipients during transplantation of the liver from cadavers and relative donors. The biopsy specimens of donor organs taken prior to grafting served as a control. Irrespective of the type of grafting, regenerative processes in the grafted liver were shown to have common regularities and to run by using the mechanisms of both intracellular regeneration and proliferation. Their maximum rate was seen within a month after grafting of a cadaverous organ and within 3 months after grafting a part of the liver from a relative donor. In cadaverous transplantation, regenerative processes depended mainly on the degree of ischemic lesions; in relative donor organ transplantation, that depended on the fitness of graft mass (the index K being close to 0.5), proliferative processes and the time of higher hepatocytic ploidity increased. An adequate evaluation of the status of a cadaverous organ, estimation of the optimum mass of a grafted hepatic part from a relative donor, and effective immunosuppressive therapy ensure required reparation rates and a complete recovery of the structure of a graft.