We adopted ultrasonic Doppler technique and real-time ultrasonotomography for the diagnosis of testicular torsion and varicocele which are the representative diseases to cause abnormalities of blood circulation of spermatic cord. The early diagnosis is of top importance for the therapeutic treatment against testicular torsion and varicocele. The ultrasonic examination we adopted for this purpose demonstrated outstanding clinical results. 1. Our ultrasonic diagnosis could attain a successful rate of diagnosis of 95% in the testicular torsion of 40 cases. For the therapy of 20 cases (50%), reduction of testis was conducted, while castration was applied to the other 18 cases (45%). No treatment was conducted for the balance 2 cases because 20 days and 32 days had passed since the onset of their symptoms in the two cases. In the cases with application of the reduction for the cure of testis, the time needed up until therapy since the onset of symptoms was minimum 1 hour up to the maximum 24 hours (8.2 hours on the average). In the cases necessitating the castration, 16 needed more than 2 days, while the balance 2 needed less than 24hours. 2. Left side varicocele was discovered in 365 cases by our ultrasonic examination. According to the method we developed for classification of varicocele, these cases could be classified into 38 cases (11%), 107 cases (30%), 99 cases (28%), and 112 cases (31%) of Groups A, B, C and D, respectively. Presence of varicocele was identified also on the right side in 118 (33%) of 356 cases. The more advanced the grade of the left-side varicocele, the higher tended to be the rate of complication of the right-side varicocele. Of 356 cases with varicocele, 89% were infertile patients, which corresponded with 38% of the total male patients with infertility. Of the total cases undergoing semen analysis, 73% showed abnormal semen findings. As the grade of varicocele was more advanced, those showing abnormal findings tended to be more. Of the patients undergoing surgical operation (high-ligation of internal spermatic vein), 36% demonstrated normalization of the findings on semen, while 22% of the patients showed established pregnancy.