1, the subject should abstain from sexual intercourse for 3-7 days before the examination; dream ejaculation should be regarded as an act of seminal emission. 2, the subject should not take testosterone propionate, testosterone phenylacetate, nandrolone phenylpropionate and other drugs within 1 week before the examination. 3, the subject should avoid alcohol, staying up late and overexertion before the examination. 4. The subject should preferably use masturbation to obtain semen, and should not use ordinary latex condoms. 5, the subject must collect the semen intact when collecting semen. 6. It is best to collect the semen in a separate room provided by the center so that it can be sent in time for testing. If the subject collects elsewhere, he/she should first receive a covered sperm cup at the nurse’s station and should send the semen to the testing room as soon as possible and keep the semen at a good temperature, which can be kept warm in an underwear pocket when sending it for testing. 7. If the subject has difficulty in taking sperm, he can prepare his own special pictures or videos in advance to be used in the process of taking sperm. 8. If there is a sperm DNA fragmentation rate test, please give the sperm retention cup, the examination application form and the sperm collection questionnaire to the staff in person. 9. Please keep the environment hygienic for the examinees.