In comparison with children with moderate asthma exacerbation non-infected Mycoplasma pneumonia, the rate of parenchymal infiltration, interstitial infiltration on chest X ray were higher (38.7% vs 15.6%, and 25.8% vs 5.7%) respectively; the mean period using bronchodilators and glucocorticosteroids were longer (5.9 (1.8) vs 4.5 (1.3) and 5.3 (1.1) vs 4.4 (1.1) days) respectively; the mean length of stay was longer (6.2 (2.0) vs 4.5 (1.3) days) in children with moderate asthma exacerbation infected Mycoplasma pneumonia (p<0.001).