The present thienopyrimidine derivatives of formula (I) and compositions having ganodotropin-releasing hormone antagonistic activity are useful as propylactics or therapeutic agents for the prevention or treatment of several hormone dependent diseases, for example, a sex hormone dependent cancer (e.g., prostatic cancer, uterine cervical cancer, breast cancer, pituitary adenoma), benign prostatic hypertrophy, myoma of the uterus, endometriosis, precocious puberty, amenorrhea, premenstrual syndrome, polycystic ovary syndrome and acne vulgaris; are effective as a fertility controlling agent in both sexes (e.g., a preganancy controlling agent and a menstrual cycle controlling agent); can be used as a male or female contraceptive, as an ovulation-inducing agent; can be used as an infertility treating agent by using a rebound effect owing to a stoppage of administration thereof; and are useful for modulating estrous cycles in animals in the field of animal husbandry, as agents for improving the quality of edible meat or promoting the growth of animals; and as agents for promoting spawning in fish.