All people have a natural desire to have their own biological children, and in reality, both men and women can face unintended circumstances that lead them to fertility preservation through cryopreservation techniques. Cryopreservation of human sperm has been used for more than 200 years now. The Italian physiologist Rev. Lazaro Spallanzani was the first to report in the 17th century that certain sperm remained alive after placing semen in cryogenic temperature and rewarming it by appropriate methods. With the development of cryobiology, the methods of sperm preservation are constantly updated. Currently, liquid nitrogen at -196°C is the commonly used cryogenic source for cryopreservation. Theoretically, spermatozoa are ideal cells to receive cryopreservation because they are relatively small in size, have a large surface area, very little cytoplasm, and contain less intracellular water compared to other cells. The principle of sperm cryopreservation is that spermatozoa are preserved at ultra-low temperatures where their metabolic activities almost cease, allowing them to be preserved in a resting state and then revived once warmed up without losing their ability to fertilize. As knowledge in assisted reproductive technology continues to advance, the indications for sperm cryopreservation are expanding, and sufficient evidence exists in the literature to demonstrate that frozen sperm is nearly identical to fresh sperm in fertilized oocytes and their subsequent growth. So who needs to undergo sperm cryopreservation? 1. Cancer patients. It is well documented that cancer treatment has a significant impact on testicular function, and the duration of this impact can be temporary or permanent. This is because certain male cancer patients will experience gonadotoxic therapy during their cancer treatment. So if they still have fertility requirements, it is necessary to provide them with sperm cryopreservation. 2.Vasectomy, sperm cryopreservation before vasectomy can be used as a fertility insurance measure, and when a vasectomy patient remarries, this method can allow him to have another child. 3.Patients with cremaster injury, electrically stimulated sperm collection samples can be cryopreserved and successfully used for assisted reproduction in patients with cremaster injury. 4, Patients with oligozoospermia and weak spermatozoa, by using several cryopreserved samples at the same time, the number of motile sperm can be increased. 5.For azoospermia requiring surgical sperm retrieval, cryopreservation of sperm can avoid multiple biopsies and microsurgery. For couples undergoing assisted reproductive treatment, the male partner may have difficulty in retrieving sperm and freeze the sperm in advance, and then thaw the sperm when the oocyte needs to be fertilized.