It seems that ICSI is well investigated basically and clinically, as more than 20 years have passed from the first report of success in human's ICSI. However, the study is still insufficient in practice. We need discussion about the unknown points in ICSI procedure, for example the in vitro ageing of retrieved oocytes, non-physiological treatment removing the cumulus cells from COC by hyaluronidase, the method of selection of good sperm, the method of immobilization of sperm, the effect of polyvinylpyrrolidone and acrosome enzyme that are brought in the oocyte. We must practice good treatments for oocytes and embryos. It is important that we continue carrying out that it is thought to be right scientifically and theoretically in ICSI procedure to improve quality of ICSI. It leads to improvement of the quality of ART and seems to be the mission of a stuff engaged in reproductive medicine.