The effect of matrine on cold ischemia and reperfusion injury of sinusoidal endothelial cells (SEC) was investigated in rats using an orthotopic liver transplantation (OLT) model. Syngeneic Sprague-Dawley (SD) rats were randomly assigned to 4 groups of 32 rats: untreated group (controls), low-dose treated group, high-dose treated group, and sham operation group (normals). After 5 hr of preservation in Ringer's solution, orthotopic implantation of the donor liver was performed. At 1, 2, 4, and 24 hr after reperfusion, 6 rats from each group were killed to collect blood and to excise the median hepatic lobe; the other 8 rats were observed to assess the 1-wk survival rate post-transplantation. All transplant recipients in the untreated group (controls) died within 48 hr, mostly between 10 to 20 hr. Matrine treatment increased the 1-wk survival rate to 75% in both treated groups. Plasma levels of hyaluronic acid (HA) at 1, 2, and 4 hr post-implantation were decreased significantly by matrine treatment. The immunohistochemical expression of intercellular adhesion molecule-1 (ICAM-1) in rat liver decreased significantly in both treated groups, and the pathological changes of SEC were ameliorated. Matrine markedly inhibited the activation of Kupffer cells and their release of tumor necrosis factor (TNF). Hepatic malondialdehyde (MDA) levels and superoxide dismutase (SOD) activities were improved by matrine administration. In conclusion, matrine can protect SEC from cold ischemia and reperfusion injury after rat orthotopic liver transplantation.