Objective To observe the changes of blood biochemistry during orthotopic liver transplantation in pigs. Methods Fourteen healthy pigs were anesthetized and intubated, the right carotic artery was cannulated for blood pressure monitoring and blood biochemical sampling. The right internal jugular vein was cannulated for central venous pressure monitoring. No exogenous glucose was administrated during operation, the donor liver was perfused with Collin’s solution. During the anhepatic stage, the veno-venous bypass was established, blood was pumped from the portal and femoral veins using an extracorporeal circuit, and returned to the axillary vein. The arterial blood was sampled for monitoring arterial blood gas tensions, Na＋,K＋,Ca2＋, and blood glucose levels.Results During preanhepatic stage, blood glucose levels increased progressively, blood electrolytes and acidbase balance were stable. During anhepatic stage, pH was decreased, base deficit was increased significantly, blood glucose levels were significantly decreased, blood electrolytes were stable. During neohepatic stage, acidosis became more severe, blood potassium increased abruptly on reperfusin of the grafted liver, blood glucose was higher than that in prehepatic and anhepatic stage. Conclusion During operation of liver transplantation, metabolic acidosis developed progressively, blood glucose decreased in anhepatic stage, blood glucose and potassium increased significantly on reperfusion of the grafted liver.