To provide an ultrasonic diagnostic system which reduces the operator's work to forecast ovulation days and enables him to forecast them with high precision.

The ultrasonic diagnosis system is provided with an ultrasonic image data generation means 1, 2, to transmit ultrasonic waves to a subject and receive them from her a display means 4 to display the ultrasonic image data as ultrasonic images, a follicle diameter measuring means 3 to measure the diameter of follicles from their ultrasonic images shown by the display means, a follicle diameter storing means 9 to preserve the follicle diameter values measured with the follicle diameter measuring means in relation with their measurement dates, and an ovulation forecasting means 8 to forecast the ovulation days of subjects.