This study was undertaken to estimate the effects of the induction agents on the bioparameters such as changes in blood pressure, pulse rate, Apgar score, patients movement, fetal arterial and venous blood gas analysis, memory and emergence reactions. 116 parturients undergoing cesarian section were divided into two groups: ketamine group and thiopental group, and were given 1.2 mg/kg ketamine in ketamine group and 4 mg/kg thiopental sodium in thiopental group as an induction agent respectively. The results were as follows; I) Blood pressure increased in both groups, but ketamine group less increased than thiopental group statistically. Pulse rate did not increased in skin incision in ketamine group statistically. 2) The patient's movement were 5 case(9%) in ketamine group and 17 cases(29%) in thiopental group. 3) There was not significant difference in fetal arterial and venous blood gas analysis. 4) In Apgar score, ketamine group is better than thiopental group. 5) There was no psychologic side reactions in both groups. 6) Postoperative recalling of intraoperative awareness occured in seven patients(12%) only in the thiopental group.