Over the period of 23 years from 1934 to 1957 out of the total of 10,000 deliveries at the Obstetrics Clinic of Okayama University Medical School those who had the abdominal cesarean section amounted to 91 cases, showing the rate of frequency of 0.91 per cent (1.08＞p＞0.76%). There is a significant difference in the frequency of the abdominal cesarean section between the years (1934-1945) before the end of the World War II and the years (1946-1957) after the end of the War, with an increase in the latter period. As for the relationship between number of delivery, age, and the frequency of the abdominal cesarean section, the frequency rate is highest in the primipara over 30 years old, followed by the multipara over 30 years, and it is lowest in the multipara under 29 years. As regards the indication, the abnormality of the pelvis is low, showing only 17.5 per cent; and this fact seems to be due to the adjustment of indications as well as to our policy in which we try to have delivery through the vaginal way as best as we can. Taking the relationship between pains, and rupture of the bag of water and operation, the section performed prior to the pains amounts to only 26.6 per cent, whereas that performed before rupture of the bag is rather frequent, namely, 80.2 per cent. Those who showed the body temperature of over 38℃ postoperatively amounted to 29 cases. The proportion of the postoperative rise in the body temperature by the methods of operation was highest in the corporeal section followed in a descending order of the cervical section and Porro's operation. However, no difference can be found in the rise in the body temperature between the section before rupture of the bag and that performed afterwards. The maternal mortality rate was 4.39 per cent (9.65＞p＞2.16%). As for the neonatal mortality rate the true death rate was 26.59 per cent (44.33＞p＞1995%), and the corrected death rate, was 10.39 per cent (17.76＞p＞6.12%). The neonatal mortality rate in mothers having the abnormality of the birth canal only was markedly lower than those with toxemias or those with hemorrhagic complications.