Once a boy is born, parents always look twice at his “balls”, which is a small sign of virility. But some boys’ “balls” seem to play hide-and-seek, with one or both scrotums empty and no testicles to be felt. In fact, this is a common disease in pediatric urology: cryptorchidism. Cryptorchidism means that one or both testicles stop on the way down and do not enter the scrotum on the same side. In children with cryptorchidism, the scrotum is smaller on one side or both sides, and there is no testicle in the scrotum on palpation. Cryptorchidism is mostly accompanied by inguinal hernia, and B ultrasound can be used as a routine preoperative examination. Hazards of cryptorchidism: 1. Testicular injury: Cryptorchidism is mostly located in the inguinal canal, and the posterior wall of inguinal canal is hard and inelastic, so it is easy to be squeezed, collision and other trauma. 2. Testicular torsion: Because of the possible abnormal development between the testicle and the lead band of cryptorchidism, torsion may easily occur. If torsion is not detected and treated in time, it may lead to testicular necrosis. 3.Spermatogenic dysfunction of testis: If cryptorchidism is not treated early, its spermatogenic ability will be low in adulthood and male infertility may occur. 4.Testicular tumor: Cryptorchidism is more likely to become malignant after stunting and injury. 5.Mental and psychological impact: Due to the empty scrotum, the position and size of the testicles are abnormal, which can make the children with cryptorchidism have low self-esteem, and the worries about infertility can cause mental pain. Since cryptorchidism has such a great harm, of course, we should take appropriate treatment methods as early as possible. There are two kinds of cryptorchidism treatment: endocrine treatment and surgical treatment. If the endocrine treatment is not effective, surgery should be performed as soon as possible. Generally, surgery is recommended before the age of 2. There are two main surgical methods: open and laparoscopic surgery. At present, the treatment of cryptorchidism in infants and children by single-site laparoscopic testicular descending fixation through the umbilicus has achieved good clinical results, especially for high cryptorchidism near the inguinal canal of infants and children; small incision next to the umbilical fossa has no obvious scar exposure after surgery; all descending fixed testicles are preserved during surgery with the testicular lead and spermatic cord of the affected side in both directions, and the blood supply of the affected testicle is good after surgery.