A gonadotropin-releasing hormone antagonistic composition, which comprises an optionally substituted condensed-bicyclic compound consisting of a homo or hetero 5 to 7 membered ring and a homo or hetero 5 to 7 membered ring is effective as a propylactic or therapeutic agent for the prevention or treatment of several hormone dependent diseases, for example, a sex hormone dependent cancer (e.g. prostatic cancer, cancer of uterine cervix, breast cancer, pituitary adenoma), benign prostatic hypertrophy, myoma of the uterus, endometriosis, precocious puberty, amenorrhea, premenstrual syndrome, polycystic ovary syndrome and acne vulgaris; is effective as a fertility controlling agent in both sexes (e.g. a pregnancy controlling agent and a menstrual cycle controlling agent); can be used as a contraceptive of male or female, as an ovulation-inducing agent of female; can be used as an infertility treating agent by using a rebound effect owing to a stoppage of administration thereof; is useful as modulating estrous cycles in animals in the field of animal husbandry, as an agent fro improving the quality of edible meat or promoting the growth of animals; is useful as an agent of spawning promotion in fish.