By the Kawasaki disease, it is important that treatment is effective before the tenth day of illness when a coronary lesion can occur, and it is a well-known fact that early disappearance of inflammation leads directly to the onset restraint of the coronary lesions. Plasma exchange (PE) removes inflammatory cytokine and chemokines in the blood for Kawasaki disease directly and suppresses the inflammation early. The treatment result of the PE for the IVIG-resistant Kawasaki disease is so good, and if it could be started before particularly coronary lesion develops, we will expect an extremely big effect. In addition, when immunoglobulin therapy, steroid pulse therapy or neutrophilic elastase inhibitor therapy is invalid, we can perform PE therapy with the insurance applica- tion in Japan.