After marriage has been cohabiting without children, if the wife by the examination is not a problem, the man should go to the hospital in time to check in order to find out the reasons for early treatment, can be in the hospital urology or men’s section of the following tests in turn. First, medical history It is very important to take a correct medical history, the doctor should be responsible and keep the patient’s confidentiality; the patient should also take the initiative to cooperate with the truthful reflection of the following: 1, occupations and types of work: whether there is contact with poisons (lead, mercury, phosphorus), radiation, whether high-temperature operations, contact time and the availability of protective measures; nutritional status; whether there is a bad hobby (cigarettes, alcohol), and so on. 2.Past medical history: whether he/she has suffered from gonorrhea, mumps, tuberculosis, epididymitis, prostatitis, pyelonephritis, cystitis or spinal cord injury, whether he/she has difficulty in urination, whether he/she has diabetes mellitus or hypothyroidism, and what is the treatment situation and effect. 3, marriage and sex life: including the attitude towards sex life, sexual intercourse and frequency, with or without spermatorrhea, impotence, premature ejaculation, etc., premarital masturbation habits; husband and wife’s relationship, the wife’s health, sexual life coordination, etc.; the length of marriage, cohabitation time, and whether to take contraceptive measures. 4, previous examination and treatment: male semen examination results, collection time and method; has been treated, how effective; female examination. Family history: whether there are patients with infertility, gender dysphoria, hereditary disease, tuberculosis, etc. in the family. Physical examination includes general body and reproductive organs examination. The whole body examination is the same as the internal medicine method, especially pay attention to the development, nutrition and mental status, but the focus is on the examination of the reproductive organs, the examination includes: 1, penis: pay attention to the presence of serious penile, hardness, inflammation, tumor or developmental abnormalities. 2, urethra: whether there is any serious penile, hardness, inflammation, tumor or developmental abnormalities. 2. Urethra: for fistula, hypospadias, hardness. 3, prostate: through the anal diagnosis can check its size, there are no hard knots, swelling, but also massage to take the prostate fluid examination. 4, testicles: measure its size, palpation hardness, there are no hard knots, pressure, swelling, whether cryptorchid testis. 5, spermatic cord: touch the hardness of the vas deferens, with or without nodules, pressure and pain, with or without varicocele. Third, laboratory tests In addition to the semen examination listed as a mandatory item, the rest should be selected depending on the patient’s specific situation: 1, semen analysis: this will help to understand the male fertility, is a mandatory item of infertility, the examination includes packet, volume, liquefaction time, acidity and alkalinity, sperm count, motility, viability, and morphology. 2, in vitro heterologous insemination experiment: even if the routine semen analysis is completely normal, but sometimes still can not fully represent the sperm insemination ability. In-vitro heterologous fertilization test can more accurately estimate the fertilization ability of sperms, which is very valuable for judging men’s fertility, and commonly used is the heterologous fertilization test in which human sperms penetrate hamster eggs, and the sperms of normal fertile people are used as the control. 3, prostate fluid examination: normal milky white, alkaline, high power microscope can be seen in the field of view of the tiny, refractive lecithin particles, a few epithelial cells, amyloid and spermatozoa, the number of leukocytes is greater than ten, there is an increase in the number of leukocytes in the case of inflammation, or even to see heaps of pus cells, lecithin particles significantly reduced. Fourth, endocrine examination through the gonadotropin-releasing hormone or clomiphene stimulation test can understand the hypothalamus – pituitary – testicular axis function. Measurement of testosterone level can directly reflect the function of mesenchymal cells. If necessary, thyroid hormone, adrenocorticotropic hormone or prolactin can be measured. Doppler ultrasonography can help to confirm varicocele. Sixth, X-ray examination in order to determine the obstruction of the vas deferens, can be used vas deferens, epididymal contrast, vas deferens, seminal vesicle contrast or urethrogram, etc., hyperprolactinemia X-ray tomography of the pterygoid plexus (positive, lateral) to determine the presence of pituitary adenoma. Immunological examination: Sperm agglutination test or braking test to detect sperm agglutination antibody or braking antibody in serum or seminal plasma. There are various testing methods, which should be chosen according to local conditions. Testicular biopsy is used for azoospermia or oligozoospermia, directly checking the spermatogenic function of testicular seminiferous tubules and the development of interstitial cells, and the synthesis and metabolism of local hormones can be reflected by immunohistological staining. Chromosome karyotype analysis is used for abnormalities of external genital organs, testicular dysplasia and unexplained azoospermia.