According to the World Health Organization Manual on Standardized Testing and Diagnosis for Infertile Couples and WHO Diagnostic Procedure Sheet for Male Infertility, the diagnosis of male infertility etiology can be divided into 16 categories: 1. Sexual dysfunction including impotence, too frequent or too little sexual intercourse, non-ejaculation, premature ejaculation (including the inability to discharge semen into the vagina due to anatomical abnormalities such as hypospadias), retrograde ejaculation (semen is not expelled from the body but retrograde into the bladder, and these patients can be found live sperm in the urine examination after collecting intercourse). 2, according to the sperm and seminal plasma examination to determine the diagnosis: (1) male immune infertility: 50% of active sperm have anti-sperm antibodies wrapped, these patients must do other auxiliary tests. (2) Unexplained infertility: normal sexual function, normal sperm and seminal plasma examination. (3) Simple seminal plasma abnormalities: these patients are not found to have accessory gonadal infection or other lesions, the significance of simple seminal plasma abnormalities causing infertility is unclear. 3, with a definite cause of male infertility classification with a definite cause of male reproduction and semen examination is azoospermia or sperm and/or seminal plasma abnormalities: (1) medical factors: due to drugs or surgery and other medical reasons caused by sperm abnormalities. (2) Systemic causes: with systemic diseases, alcoholism, drug abuse, environmental factors, recent hyperthermia or ciliary dyskinesia syndrome (poor sperm viability with a history of chronic upper respiratory tract disease, etc.). (3) Congenital anomalies: including cryptorchidism, or abnormal cell karyotype analysis causing sperm abnormalities, and azoospermia due to congenital hypoplasia of the seminal vesicles and/or vas deferens, as well as other congenital disorders affecting fertility. (4) Acquired testicular damage: such as mumps-induced orchitis or other factors causing testicular damage resulting in testicular atrophy and testicular volume <15 ml, along with sperm abnormalities. (5) Varicocele with sperm and/or seminal plasma abnormalities causing infertility If there is varicocele but semen analysis is normal, then it should be classified as unexplained infertility. (6) Infertility of male accessory gland infection: If the patient has oligospermia, weak spermatozoa or abnormal spermatozoa and has the following criteria Infertility of male accessory gland infection may be diagnosed when all of the above tests are available and any combination of the following is present: history or signs of prostatitis; or history or signs of abnormal semen examination; or prostatitis manifestations accompanied by abnormal ejaculate semen; or at least two abnormalities in each semen examination. (7) Endocrine causes: there may be signs of hypogonadism, normal blood sex hormone measurement of FSH, and low testosterone or repeatedly high PRL measurement. These cases must be further examined to clarify the diagnosis, such as visual field, butterfly saddle scan, LHRH, TRH, etc. 4.Other cases where no definite cause is identified but only abnormal semen examination, such as oligospermia, weak spermia, teratozoospermia or azoospermia, are diagnosed according to the following criteria: (1) Idiopathic oligospermia: sperm with sperm but sperm density <20×106/ml. (2) Idiopathic weak spermia: sperm with normal density but fast forward moving sperm <25%. (3) Idiopathic teratozoospermia: normal sperm density and viability but <30% normal sperm head morphology. (4) Obstructive azoospermia: no spermatozoa on semen examination, but testicular biopsy proves that spermatozoa occur in the varicocele. If testicular biopsy is not performed, the initial diagnosis can be made on the basis of normal testicular volume (total volume ≥ 30 ml) and normal FSH. (5) Idiopathic azoospermia: no spermatozoa in the semen without identifying the cause, accompanied by testicular volume reduction (total testicular volume <30ml) and increased FSH, or testicular biopsy to confirm the absence of spermatozoa in the varicocele.