The complex etiology of male infertility is broadly divided into three categories: pre-testicular factors; testicular factors; and post-testicular factors. (A) pre-testicular factors: endocrine infertility (hypogonadotropic hypogonadism; 5ą-reductase defects); systemic diseases (such as glucocorticoid excess or Cushing’s syndrome, nutritional deficiency, obesity, etc.). (B) testicular factors: 1, chromosomal abnormalities (such as klinefeter syndrone, Y chromosome microdeletion, cilia immobility syndrome, bilateral vasoductal dysplasia or agenesis, androgen receptor mutation); 2, congenital or developmental abnormalities disease (such as cryptorchidism, only Sertoli cell syndrome); acquired diseases (varicocele, viral orchitis, environmental toxins) Sexual testicular injury: (ionizing radiation, heavy metals, high temperature, smoking, alcoholism); systemic diseases (liver cirrhosis, chronic renal insufficiency). (iii) post-testicular factors: infarct azoospermia, epididymal necrospermia, genitourinary tract infection, erectile dysfunction, ejaculatory dysfunction, abnormal intercourse, immune infertility (anti-sperm antibodies).