Inguinal hernia is one of the most common surgical conditions. In adults, inguinal hernias are predominantly hiatal hernias and some straight hernias, whereas inguinal hernias in children are almost always hiatal hernias and their pathogenesis is due to a congenital factor, the failure of the sphincter to close. During embryonic development, the testis located on the posterior abdominal wall gradually descends downward, pushing the peritoneum forward near the internal inguinal ring to form the sheath, with the testis immediately behind the peritoneal sheath and gradually descending to the scrotum. Under normal development, the sphincter begins to atrophy shortly after birth, except for the intrinsic sheath that forms near the testis, which completely closes into a strip of tissue. If the peritoneal sphincter fails to close and remains open, a so-called unclosed sphincter is formed, which is the main cause of inguinal hernia and syringomyelia in children. In addition, other factors such as weakness of the internal oblique and transversus abdominis muscles and short inguinal canal in children also play a role in the development of inguinal hernia in children. If the entire sphincter canal is not closed, the abdominal contents can reach the scrotal area along the sphincter (hernia sac), which is the majority of cases. In the other case, the sphincter is partially occluded near the testis and the spermatic cord is not closed, the hernia sac stops at the spermatic cord and the inguinal mass is smaller and does not reach the scrotum, which some call a spermatic hernia. However, in principle, there is no difference between these two in terms of treatment. The most common abdominal organ that enters the hernia sac is the small intestine, which is probably the reason why inguinal hernias are commonly known as small bowel pneumonia and hernias. If the small intestine is prolapsed for a long period of time and cannot be retracted in the area of the hernia sac ring, it is an inguinal hernia. When the small intestine enters the hernia sac, the blood circulation of the small intestine is impaired, which can cause severe pain in the child, and in severe cases, nausea, vomiting, abdominal distention, blood in the stool and fever. In addition, the prolonged pressure on the spermatic cord can lead to testicular ischemia and testicular infarction in infants and children with an incarcerated hernia. Although the incidence is not as high as in boys, inguinal hernia is also found in girls. Because of the proximity of the inner ring opening to the ovaries and fallopian tubes, it is common for the hernia contents in girls to include the ovaries and fallopian tubes in addition to the small intestine, and during the descent of the ovaries to the hernia sac, torsion of the vascular tissues of the ovaries can be combined, so in girls, ovarian necrosis may occur even without compression at the ring opening site. In addition, in girls, the fallopian tube, ovarian tract and even the uterus can descend with the sphincter as part of the wall of the hernia sac, forming a so-called slip hernia, which is relatively more complicated to manage surgically. Although the peritoneal sphincter can remain occluded after birth and there are occasional clinical cases of spontaneous healing of inguinal hernias in children, it is indisputable that spontaneous healing of inguinal hernias is highly unlikely and the price of waiting for spontaneous healing may be the occurrence of ingrown hernia. The treatment of inguinal hernia is mainly surgical and we do not recommend the use of hernia belts, against injection therapy. The purpose of a hernia belt is to reduce the chance of abdominal contents entering the hernia sac and does not improve the chance of sphincter closure. Injections are used to increase the chances of hernia sac closure by local injection of sclerosing agents, but their success rate is low. More importantly, severe local scar formation after injection may affect the blood supply to the testes and the patency of the vas deferens, and make reoperation significantly more difficult. Parents are advised to consider carefully when choosing a treatment method. High ligation of the hernia sac is the classic treatment for pediatric inguinal hernia, which involves separating the sphincter close to the abdominal cavity and ligating the side close to the abdominal cavity so that the abdominal cavity is no longer connected to the sphincter. The technique is very mature and safe, with a simple procedure, small incisions, minimal trauma and a very low recurrence rate. Since the hernia sac is close to the vas deferens, there are many parents who worry whether inguinal hernia will affect fertility. In practice, as long as the hernia sac is carefully separated, damage to the vas deferens can be completely avoided. High ligation of the hernia sac is less invasive and can theoretically be performed in the neonatal period, but considering the relatively small chance of inguinal hernia entrapment and the thinness of the hernia sac in children within 6 months of age, the operation is rarely routinely performed within 6 months in China. However, for cases such as incarcerated hernia that cannot be repositioned by manipulation, those with a history of incarcerated hernia, and giant hernia, surgery should be performed as early as possible and, from the experience of the author and colleagues, safely. Season and climate do not affect the choice of surgery time. For children with serious diseases, such as cyanotic congenital heart disease, malnutrition, liver and kidney disease or other diseases in the acute stage, it is appropriate to postpone surgery.