The etiologic factors of impotence are psycholagic, endocrinopathic and neuropathic caues. In diabetes, the organic factors are more important than psychologic factors, because number of diabetic men were unable to experience of morning erection or erection by masturbation. For the study of endocrinopathic couses, 17-KS, testosterone, androsterone aad etiocholanolone in urinc were measured. The testosterone and its metabolites were measured (for diabetics) in 24 hour urine 25 and l8 healthy Korean men with the method of Koji Nakashima and Mitsaaki Tajiri by gea-chromatogrephy, The results are as followings: 1. The mean proportion of measurements of testosterone and its metabolites were 2. 46+-1.487 mg/day in diabeties and 3.67+-1.526mg/day in healthy men. (p<0.05) 2. In age group of diabeties, the mean value in the ages over 50 was 1. 967mg/day, and lower in the age of under 50 was 2.724 mg/day. According to the aging difference of the mean vaIue was more prominent in diabetics with impotence, (1.494 mg/day3 than in diabetes without impotence (9. 343 mg/day). 3. In this study, the measurements were no apparent relationships between the blood sugar level and the duration of diabetes,