During orthotopic liver transplantation (OLT), changes of hemodynamic, electrolytes and acid-base balance are frequently occurred. These changes may influence mortality and prognosis during and after surgery. The purpose of this study was to observe and evaluate the changes of hemodynamics and electrolytes occurring in 14 cases canine OLT. After insertion of endotracheal tube, anesthesia was maintained with 1%enflurane and pancuronium bromide. Swan-Ganz catheter(7.5 Fr.) was inserted into right external jugular vein and 20 gauge angiocatheter was also inserted into left femoral artery. Complete hemodynamic variables and electrolytes were measured 30 minutes after skin incision, anhepatic stage, 5 minutes before reperfusion, 5 and 30 minutes after reperfusion. The results were as follows; On reperfusion of grafted liver, 9 cases(64%) showed postreperfusion syndrome. In 9 cases showing Postreperfusion syndrome, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure were decreased and serum potassium concentration was increased on reperfusion, but there were no significant changes in central venous pressure, pulmonary capillary wedge pressure, heart rate, body temperature and serum ionized calcium concentration when comparing with before reperfusion. Decreased mean arterial pressure during reperfusion in postreperfusion syndrome might be speculated through decrease of myocardial contractility and systemic vascular resistance.