Orchidism, also known as congenital testicular agenesis, is characterized by unilateral or bilateral simple absence of testes at birth, with male external genitalia and no sex chromosome abnormality. It is rare clinically and is divided into two categories: unilateral and bilateral testicular agenesis. Typical symptoms include absent testes, gonadal hypoplasia, and decreased blood testosterone. In anorchidism, the embryonic period is characterized by complete atrophy of the testes due to infection, trauma, vascular embolism, or testicular torsion, and the phenotype is male. The male secondary sex characteristics do not develop at puberty, and the external genitalia remain infantile and testicular-free, and if androgen therapy is not given early, a eunuch phenotype develops. If there are residual or ectopic mesenchymal cells secreting androgens, modest secondary sexual characteristics may develop. Blood testosterone levels are low, gonadotropins are significantly elevated, and testosterone does not increase after HCG stimulation. 1.Disordered gonadal development due to some factors interfering during embryonic development Lobacarro et al. believe that SRY gene abnormality on the sex-determining region of the Y chromosome may lead to anorchidism. 2, testicular torsion during pregnancy or shortly before or after birth vascular embolism of the spermatic cord causing obstruction of blood supply to the testis and atrophy of the testis may be the most common cause.