According to the duration of chemotherapy before operation, I classified into five groups (that is, from group I to group V), 77 cases, which were diagnosed as renal tuberculosis, on which nephro-ureterectomy was performed, and also examined the relation between the duration of chemotherapy and the morbid change of ureter; and came to the following conclusion.
1) Clear parallel relations could not acknowleged among ureter swelling, caseous mass of ureteral lumina and the duration of chemotherapy.
2) In the frequency of the cases in which ureters were broken, there could not be acknowledged any difference among all groups. In the frequency of epithelial regeneration, the generation was acknowledged in none of the 18 cases on which chemotherapy was not performed, but it was aknowledged in 6 of 48 cases on which chemotherapy was performed.
3) In the frequency of tubercles which ware acknowledged in those cases, there could be acknowledged no difference between each group, but in the tubercles of the cases on which chemotherapy was performed, a surrounding of connective tissue could be aknowledged.
4) The longer chemotherapy was performed, the fewer were tuberculous bacilli of the group. Tuberculous bacilli were akcnowledged in 8 of 77 cases (taht is, 10.4%).
5) In the cases in which the urinary bladder was affected, caseous mass of ureteral lumina was ack-knowledged 57.2% and was clearly more, compared with 42.9% of the cases in whch the urinary bladder was not affected.
6) Lower ureteral stenosis was aknowledged in 4 cases. Of these four, one belonging to group I was owing to the abundance of caseous mass, and the other three cases were owing to fibrous stenosis.