According to the World Health Organization (WHO), if a couple has lived together for more than one year without using any contraception and the woman is infertile due to male factors, it is called male infertility. Worldwide, about 15% of couples of childbearing age suffer from infertility. Male infertility patients generally need to do the following examinations. I. Physical examination: Examination of the male reproductive system (testicles, epididymis, vas deferens, spermatic vein, penis, foreskin and urethral opening, etc.), and examination of secondary sexual characteristics (beard, laryngeal nodes, breasts, pubic hair, etc.). It is suitable for every infertility patient. Semen examination: Patients are required not to ejaculate for 3~5 days before the semen examination, and usually masturbation method is used to collect semen, which mainly includes the following examinations: 1. Routine semen analysis: mainly including semen volume, sperm density, sperm motility (percentage of forward motion or a+b class sperm) and sperm morphology staining analysis. It is applicable to every infertility patient who visits the clinic. 2. Biochemical analysis of seminal plasma: mainly including neutral alpha-glucosidase and fructose, reflecting the function of epididymis and seminal vesicle and their patency respectively, applicable to azoospermic patients suspected of having obstruction of vas deferens. 3.Analysis of semen infectious indexes: mainly including semen leukocyte peroxidase staining and seminal plasma elastase, applicable to patients suspected of having reproductive glandular infection. 4. Anti-sperm antibody (AsAb) test: mainly checking anti-sperm antibody in semen, anti-sperm antibody in men’s serum is of little significance; the main test method is semen mixed antiglobulin test (MAR test). It is suitable for patients with poor sperm vitality, more sperm agglutination or unexplained infertility. 5. Sperm acrosome reaction analysis: including sperm acrosome integrity rate and sperm acrosome enzyme activity analysis, which to some extent reflects the ability of sperm to fertilize the egg cell. It is suitable for patients with unexplained infertility, infertility patients who are ready to do artificial insemination or IVF. 6. Sperm nuclear DNA fragmentation analysis: applicable to infertile patients whose female partner has unexplained miscarriage and embryo abortion. Serum sex hormone test: It 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: 1. Ultrasound of the scrotum and its contents for patients suspected of having varicocele, testicular or epididymal diseases; 2. Transrectal ultrasound for examination of prostate, seminal vesicle glands and ejaculatory ducts for patients with azoospermia, severe oligozoospermia, low volume of seminal fluid or hematospermia. Genetic examination such as peripheral blood karyotype analysis and Y chromosome microdeletion test: Peripheral blood karyotype analysis is suitable for patients with azoospermia, severe oligozoospermia, primary testicular dysplasia, and unexplained miscarriage and embryo abortion of the female partner; Y chromosome microdeletion test is suitable for patients with azoospermia, severe oligo- and weakly aberrant spermatogenesis. Sixth, seminal vesicle and vasovaginography: trauma and risk, suitable for patients with infertility who are suspected of ejaculatory duct or vas deferens obstruction and are ready for surgical treatment. Testicular biopsy: The main surgical methods include sharp forceps puncture, biopsy gun puncture and incisional biopsy, etc. The purpose is to understand the function of testicular spermatogenesis. It is mainly used for patients with azoospermia, especially those who are ready to undergo IVF or vasovaginal tract reversal surgery.