It was Observed required doses of morphine and pancuronium bromide or d-tubocurarine in 34 cases of open heart anesthesia which performed between October 1, 1974 and August 31, 1975 is SNUH with the induction of sleeping dosea of 2.5% thiopental and succinyIcholine for intubation, and maintenance of 50% of nitrous oxide and oxygen. It was obtained the results as followings: 1. The average required dose of morphine in open heart anesthesia was 0.34±0.25 mg/kg body weight (34 cases). 2. The average required dose of pancuronium bromide in open heart anesthesia was 0.212±0.091mg/kg body weight (28 cases). 3. The average required dose of d-tubocurarine in open heart anesthesia was 0.745±0.298 mg /kg body weight (8 cases); 4. The duration of open heart anesthesis and extracorporeal circulation were 396 minutes and 102.8 minutes respectively. 5. Discussion on the small dose of morphine in open heart anesthesia performed with literatures.