To study the effectiveness and safety of Qingfei Oral Liquid for phlegm-heat obstructing lung syndrome in children virus pneumonia.Methods:A total of 507 cases of phlegm-heat obstructing lung syndrome in children virus pneumonia were studied in two-stage and six-center randomized controlled clinical trials.Qingfei oral liquid was used in treat group，while ribavirin injection was used in control group.Results:Two-stage clinical trials showed that the effect of Qingfei Oral Liquid was significantly better than that of ribavirin injection(P<0.05).Conclusion:Qingfei Oral Liquid is effective and safe in treating phlegm-heat obstructing lung syndrome in children virus pneumonia.