Electrodiagnostical determination of Rheobase and Chronaxy has been carried out on 10 women during pregnancy, beginning labour and puerperium. Rheobase and Chronaxy were marked in a Strength-Duration Curves scheme as well as some other points within that scheme. As a base of rise of the gained curves the actual rise at the point of the chronaxy was calculated. Our results show that with all 10 women the t-Difference-Test showed a significantly much lower curve during labour than that obtained during pregnancy. The same applied to the rise of the curve obtained during labour, which was significantly much lower than that during puerperium. There was no significant difference between the curves obtained during pregnancy and puerperium. The significance of the decline of the actual rise at the point of the Chronaxy of the Strength-Duration Curve before starting of labour as a physiological method of functional diagnostic will be discussed there under.