The common causes of pediatric fever are the following: First, respiratory system infections, children’s respiratory immune function is relatively weak, when infected by pathogenic bacteria, or when various factors such as the presence of cold, it is easy to suffer from upper respiratory tract infections, lower respiratory tract infections, and other factors that lead to fever in children. Second, common is the digestive system infection, children’s spleen and stomach function is relatively weak, or when some pathogenic bacteria infection, such as eating undigested food, or eating unclean food, it is easy to produce gastrointestinal tract disease, in addition to causing nausea, vomiting, bloating, diarrhea and other digestive symptoms, often accompanied by fever. When pathogenic bacteria invade the nervous system, such as the blood-brain barrier, it is easy to develop encephalitis, meningitis and other diseases, and fever can also occur. Fourth, it is common to have urinary tract infections, such as frequent urination, urgent urination, painful urination, and fever after being infected by the urinary tract. In conclusion, the above are the common causes of fever in children.