According to the World Health Organization (WHO), couples who have lived together without any contraceptive measures for more than one year and whose female partner is infertile due to male factors are called male infertility. In the world, about 15% of couples of reproductive age have infertility problems. Male infertility patients generally need to do the following tests. I. Physical examination: Examination of the male reproductive system (testes, epididymis, vas deferens, spermatic veins, penis, prepuce and urethra), examination of secondary sexual characteristics (beard, throat knot, breast, pubic hair, etc.). It is applicable to every infertility patient who visits the clinic. Second, semen examination, requiring patients not to ejaculate for 3~5 days before semen examination, generally using the masturbation method to extract semen, mainly including the following examinations: 1. Semen routine analysis: mainly including semen volume, sperm density, sperm motility (percentage of forward motion or a+b level sperm) and sperm morphological staining analysis. It is suitable for each infertility patient; 2. Seminal plasma biochemical analysis: mainly includes neutral alpha-glucosidase and fructose, reflecting the function of epididymis and seminal vesicles and their patency, respectively, for azoospermia patients suspected of having vas deferens obstruction; 3. Semen infectious index analysis: mainly includes semen leukocyte peroxidase staining and seminal plasma elastase, for patients suspected of having gonadal infection; 4. , anti-sperm antibodies (AsAb) test: mainly to check the anti-sperm antibodies in semen, the significance of anti-sperm antibodies in male serum is not significant; the main examination method is semen mixed antiglobulin test (MAR test). It is suitable for patients with poor sperm viability, more sperm agglutination or unexplained infertility; 5. Sperm acrosome reaction analysis: It includes sperm acrosome integrity rate and sperm acrosome enzyme activity analysis, which to some extent reflects the ability of sperm to fertilize egg cells. It is suitable for patients with unexplained infertility and infertile patients preparing for IUI or IVF; 6. Sperm nuclear DNA fragmentation analysis: it is suitable for infertile patients with unexplained miscarriage and embryonic abortion in the female partner. III. Serum sex hormone test: mainly includes testosterone (T), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), estradiol (E2), etc. It is suitable for patients with azoospermia, severe oligospermia and sexual dysfunction. IV. Ultrasound examination: 1. Ultrasound of scrotum and contents, for patients suspected of having varicocele, testicular or epididymal diseases; 2. Transrectal ultrasound, to examine prostate gland, seminal vesicle gland and ejaculatory duct, for patients with azoospermia, severe oligospermia, low semen volume or hematospermia. V. Genetic examination such as peripheral blood karyotype analysis and Y chromosome microdeletion detection: peripheral blood karyotype analysis is suitable for patients with azoospermia, severe oligospermia, primary testicular dysplasia and unexplained miscarriage and embryonic abortion in the female partner; Y chromosome microdeletion detection is suitable for patients with azoospermia, severe oligo- and hypomorphic spermatozoa. Sixth, seminal vesicle and vasectomy: invasive and risky, suitable for patients with suspected ejaculatory duct or vas deferens obstruction and ready for surgical treatment of infertility. VII. Testicular biopsy: The main surgical methods include sharp forceps puncture, biopsy gun puncture and incisional biopsy, etc. The aim is to understand the spermatogenic function of the testes. It is mainly used for patients with azoospermia, especially those who are ready for IVF or vasectomy.