Abstract: Purpose and Methods : Female Wistar rat s were fed with iodie2deficient diet for 4 months inducing iodine-deficient diseases , then put 3 female with one male to mate each other for 5 days , and to observe the effects on female fertility and carcinogenesis. Results : In group of iodine deficiency , the average intake of iodine per animal was 0. 926μg/ day , it meaning ext remely deficient . Their weight of thyroids was obviously increase , and showed simple goiter and nodular goiter. The number of living fetus significantly decrease to 6. 7 ±2. 6/ pregnant rat , comparing with cont rol 10. 4 ±2. 1/ pregnant rat , P < 0. 01. The number of ovulation was also decrease to 11. 6 ±1. 9 , comparing with cont rol 14. 8 ±2. 1 , P < 0. 01. The f requency of thyroid carcinoma was 33. 3 % (7/ 21) , comparing with cont rol 0. 0 %(0/ 12) , P < 0. 01. All thyroid carcinomas were histologically derived f rom the base of follicular hyperplasia. Conclusion : The result s mentioned above shows that the iodine deficiency must be decreasing the fertility , and having the st rong carcinogenesis to the thyroids of female rat s. Iodine-deficient goiter is the precancerous lesion of the thyroid carcinoma.

Key words: Iodine-deficiency, Rat s, Thyroid carcinomas, Fertility, Carcinogenesis