1.Abstinence should be 3-7 days before taking semen for examination. 2.Methods of semen collection: ① Masturbation method (taken in the sperm extraction room, such as sperm extraction at home need to be delivered within half an hour, and accurate records of the time to take out semen and the number of days of abstinence). ② Semen apparatus taking method (Note: intercourse interruption method is prohibited because this method will lose the first part of semen, which has the highest sperm density). 3. Specimen rejection criteria: ① The entire ejaculated semen is not collected. ② Too long transportation time (more than 1 hour): can affect sperm viability. ③ Overflow of the semen container. ④ Condom with latex or plastic products. ⑤ Contaminated specimens. 4. Specimen storage or transfer: temperature 25°C-35°C, preferably kept warm in winter in an underwear pocket, and attention to prevent the bottle from being inverted and delivered within half an hour. 5.If you take the prostate fluid for examination first, it is better to take the semen for examination at an interval of 2-6 hours or at an interval of 1 day (the liquefaction time is affected by the reduction of liquefaction factor secreted by the prostate gland) 6.If I have special circumstances, such as the number of days of abstinence is not known and the name and other information is not clearly written, please inform the examiner. 7.Abstinence for 3 days for those under 25 years old, 5 days for those between 25 and 35 years old, and 7 days for those over 35 years old.