Children occasionally stay up late generally will not have much harm, but if long-term excessive late night, may cause harm mainly in the following aspects: affect the secretion of growth hormone, lead to lower body resistance and immunity, cause indigestion or constipation. 1. affect the secretion of growth hormone: growth hormone is secreted more in the process of the child’s sleep, if the child stays up late, especially for a long time, resulting in a long period of insufficient sleep, it is easy to have an impact on the secretion of growth hormone, which may have an impact on the growth of height. 2. Lead to the body resistance and immunity to reduce: the child in the sleep can make the body to get enough rest and adjustment, if the child stays up late, especially long-term excessive late night, resulting in the body can not get enough rest, which may cause the body immunity and resistance to reduce. 3. Impact on the digestive system: children due to stay up late, resulting in insufficient sleep, resulting in the brain and the body can not get enough rest, easy to affect the mood, which in turn affects the digestive system, causing indigestion or constipation. It can be seen, children long-term excessive late night is some harm, therefore, parents should let the child regular routine, to ensure that every day sleep enough; if there are symptoms of physical discomfort, should be as soon as possible to seek medical attention.