To ascertain whether ovary affects directly on the function of adrenal gland without the cooperation of hypophysis, rats were hypophysectomized and weight of adrenal gland, thickness of various zona of adrenal gland and histopathological changes were compared with those of control group during the period from 1 to 56 days. The results were summarized as follows; 1. No significant difference of adrenal gland weight was observed between hypophysectomized group and hypophysectomized and hexestrol administered group, but the adrenal gland weight of both experimental groups reduced consistently after hypophysectomy and high significant difference (P$lt;0.01) was observed compared with normal group from 7th day. 2. No significant alternation of the proportional size of adrenal zona was observed between hypophysectomized group and hypophysectomized and hexestrol administered group, but the marked atrophy of zona fasciculata and reticularis of both groups were found, and it showed significant difference (P$lt;0.05) from 7th day and high significant difference (P$lt;0.01) from 14th day whereas no difference of zona glomerulesa was observed between compared groups. 3. There was no difference of histopathological changes of gonad between hypophysectomized group and hypophysectomized and hexestrol administered group, but no atrophy of zona fasciculata and reticularis was found in experimental groups whereas zona glomerulesa and adrenal medulla was not altered compared with these of control group. These results indicate that ovary does not affect directly on the development of adrenal gland, but cooperate with the hypophysis.