To observe the clinical effect and safety of Reduning injection combined with erythromycin in treating children mycoplasma pneumonia(phlegm heat obstructing lung symptom).Methods:A total of 120 children with myicoplasma pneumonia(MPP) who enrolled from January 2012 to December 2013 were recruited. Choose 60 children as the treatment group which was treated by Reduning injection combined with erythromycin and 60 as the control group which was treated by erythromycin solely. Indexes including total symptom scores of TCM and western medicine, cardinal symptoms, symptoms disappeared time, hospital stays, total effective rate, clinical symptom and safety of the two groups were observed and compared.Results:The cardinal symptom, symptoms disappeared time and hospital stays of the treatment group are obviously better than those of the control group(P<0.05 orP<0.01). Besides, symptom scores of TCM of the treatment group are better than those of the control group except for items as pain caused by cough, blood stained sputum, bitter mouth and dry throat (P<0.05). Also, the total effective rate of the treatment group is higher than the control group without statistical significance. No toxic or side effects were observed.Conclusion:Clinical effect and safety of Reduning injection combined with erythromycin in treating children mycoplasma pneumonia(phlegm and heat obstructing the lung) is better than applying ertthoromycin alone.