We encountered with four child patients infected with a new type of influenza virus. All the cases were complicated by severe dyspnea. This study was to review the clinical picture of the influenza, and some problems that confronted us in the course of treatment. The four patients had not been vaccinated. Three of them had a history of bronchial asthma. Two developed a fever and dyspnea all at once, and the other two had acute dyspnea in less than nine hours after the attack of fever. Antiviral agents were totally useless for preventing the disease from worsening. The clinical features were exacerbated asthma, pneumonia, air leak, and plastic bronchitis. Two children were mechanically ventilated. All the patients were given corticosteroids in addition to antiviral drugs (the methylprednisolone pulse therapy given to three patients). Two patients were administered with sivelestat. All the patients recovered their illness. There was no incidence of nosocomial infestion. Keeping watch for any change in the condition of the respiratory organs is needed in the infantile case of a new type of influenza regardless of whether or not the patient has a history of bronchial asthma. The new influenza may suddenly become worse. It is almost impossible to contain the virus with antiviral drugs. Early vaccination is of cardinal importance before influenza spreads around the world in seasonal epidemics.