Continuous hyperthermic peritoneal perfusion(CHPP) has been used for patients with advanced gastric cancer and peritoneal seeding. Changes in hemodynamic, arterial blood gas, acid-base balance, electrolytes and body temperature were evaluated in 10 patients with advanced gastric cancer during CHPP. 1) Cardiac index, heart rate and mean arterial pressure were significantly increased. Systemic vascular resistance index was significantly increased at 10 min. after start of CHPP and signihcantly decreased after 30 min. Central venous pressure was very increased during CHPP. 2) Arterial oxygen tension was gradually decreased and arterial carbon dioxide tension was not changed. Significant metabolic acidosis was developed during CHPP. 3) Sodium was significantly increased and ionized calcium was significantly decreased. Potassium was not changed. 4) Temperature of midesophagus was increased mean 3.8 degrees C at 50 min. after start of CHPP. In conclusions there were significant changes in hemodynamics, arterial blood gas, acid-base balance, electrolytes and body temperature during CHPP. We should need complete preparation, careful monitoring and attention during and after CHPP.