Children’s fever white blood cells over three times may be caused by bacterial infection, Kawasaki disease and so on. 1. Bacterial infection: when bacteria and other pathogens invade the human body, it will lead to the normal function of the body’s metabolism and tissue structure is damaged, thus causing local tissue and systemic inflammatory reaction, which may lead to the children’s fever leukocytes more than three times, accompanied by diarrhea, vomiting, nasal congestion and other symptoms. 2. Kawasaki disease: children fever white blood cells more than three times may be due to Kawasaki disease, the disease is mainly related to immune factors, genetic factors, infection, accompanied by skin rash, mucous membrane congestion, lymph node enlargement and other symptoms. Children’s fever white blood cells more than three times, there may also be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.