Semen analysis – Matters that must be noted for semen specimen collection: 1. Abstinence must be practiced before semen specimen collection, usually for 3-5 days, and not more than 7 days at most. It is best to wash the vulva with soap and water, especially for circumcised patients; 2. It is best to collect the specimens by masturbation in the hospital specimen collection room. Interrupted intercourse method and use of condoms for sperm collection are strictly prohibited; 3. The collected specimen must be the whole segment of semen and held in the container provided by the laboratory and cannot overflow; 4. The laboratory staff should be informed of the specific time of semen collection. Any omissions and other relevant circumstances; 5. If not collected in the hospital, the semen specimen must be delivered to the laboratory within 1 hour; 6. After the semen specimen is collected, its temperature should be maintained at 25℃-35℃ during the transfer to the laboratory, and should be placed in the underwear pocket if in winter. If it is lower than 20℃ or higher than 40℃, it will affect the sperm vitality, activity rate and semen liquefaction, and its analysis results will have no clinical reference value; 7. If the sexual life is very frequent in the past 1 month, even if the abstinence is about 7 days, it is not advocated to do semen analysis recently. Otherwise, it is possible that the sperm density will be very low.