Disclosed are a gonadotropin releasing hormone receptor antagonist and a pharmaceutical composition including the same, which can be useful in preventing or treating a sex hormone-related disease such as endometriosis, amenorrhea, irregular menstruation, uterine myoma, uterine fibroids, polycystic ovarian disease, lupus erythematous, hypertrichosis, precocious puberty, short stature, acne, alopecia, gonadal steroid-dependent neoplasms, gonadotropin-producing pituitary adenoma, sleep apnea, irritable bowel syndrome, premenstrual syndrome, benign prostatic hyperplasia, contraception, and infertility, as well as Alzheimer disease.