The examination of male infertility includes semen examination, related microbiological examination, endocrine examination, genetic examination, etc. Although there are many examinations, it does not mean that every male infertility patient needs to do a full set of male infertility examination. The reason for this is to identify the cause as early as possible and to provide targeted treatment. Principles of male infertility tests There are many causes of male infertility, so after taking a medical history it should be combined with physical examination, such as if the patient has cryptorchidism, in addition to laboratory tests, and if there are endocrine factors it should be combined with MRI to see if there is a pituitary tumor in the skull. These tests usually follow the following principles: 1. Male infertility tests generally range from non-invasive to invasive tests. 2, male infertility tests if the cause is not found to be combined with female exclusion. 3, try to use simple and effective examination methods, the more expensive examination is placed at the end. Male infertility routine examination 1, semen routine examination This is the most basic and important clinical indicators to determine male fertility, the parameters of the semen is the first thing the doctor needs to know, the patient should pay attention to: 3-5 days of different rooms during the examination; the best way to take specimens by masturbation; to ensure that all the semen is obtained; 1-2 times in 2 weeks to recheck. 2, seminal plasma biochemical examination The analysis of the chemical composition of seminal plasma helps to understand the function of epididymis, prostate and seminal vesicle gland. If the patient has low semen volume, azoospermia, oligospermia, unexplained decrease in sperm motility, congenital defects of accessory gonads and accessory gonadal diseases, etc., seminal plasma biochemical examination can be done, which commonly includes fructose, carnitine, acid phosphatase, etc. The pathogenic microorganisms related to male urinary and reproductive system infections include bacteria, viruses, spirochetes, mycoplasma, chlamydia, etc. Commonly, gonococci, papillomavirus, adenoplasma, chlamydia trachomatis, etc. Endocrine examination Reproductive endocrine dysfunction affects male sexual and reproductive function and is an important cause of male infertility. Endocrine examination is mainly related to the determination of sex hormones T, FSH, LH, PRL, E2 and various excitation tests, such as HCG stimulation test. 5, genetic examination The normal chromosomes and genes related to males are the basis for maintaining normal reproductive function, and abnormal chromosomes and genes can lead to abnormal sexual differentiation and/or sperm production disorders, thus seriously affecting reproductive function. Females accompany with the examination.