University of Wisconsin solution (UW) enabled us to preserve whole liver for up to 24 hours and the preservation efficacy of UW has been confirmed at the hepatocellular level. However, we consider preservation of the vessels in the liver to be no less important than that of parenchymal cells to maintain liver function. Rabbit portal veins with and without endothelium were suspended in an organ chamber to measure contractile force. After various incubation periods (4°C) in Krebs solution or UW solution, veins were treated with norepinephrine (10-4 to 10-5M, 36°C, 95% O2 and 5% CO2) . Veins without endothelium contracted more after 24, 48, and 72 hours of treatment with UW (84%, 83%, and 65% of control) than after treatment with Krebs solution alone (56%, 44%, and 31%) . Veins with endothelium contracted less after 24, 48, and 72 hours of treatment with UW (138%, 119%, and 118%) than after treatment with Krebs solution alone (207%, 237%, and 213%) . These results suggest that UW preserves the contractile function of portal vein with and without endothelium for at least 48 hours.