Fifteen cases of viral pneumonia in infants were treated with refined interferon-alpha and antibiotics. Clinical symptoms of the cases with IFN-alpha were relieved in 1.40-2.79 days, earlier than those of the control. Clinical recovery time was on the average shorter than that of the control by 1.9 days, and complete recovery by 1.5 days. The difference is statistically significant. It suggested that the clinical effect of IFN-alpha together with antibiotics is better than that of antibiotics alone. There was no significant change between the experimental and control groups in absolute lymphocyte count Ig and T-cell, but OKT3 increased and OKT8 decreased slightly. The study shows that IFN is an effective and safe administration for viral pneumonia.