Abstract: Objective:To evaluate the efficacy and safety of the early treatment of severe mycoplasma pneumoniae pneumonia(MPP) with glucocorticoid in children.Methods:Forty-one severe MPP children were divided into the early glucocorticoid treatment group(22 cases) and late glucocorticoid treatment group(19 cases),and treated with azithromycin combined with conventional method.The early treatment glucocorticoid group was additionally treated with 0.2 to 0.5 mg·kg^-1·d^-1 of dexamethasone everyday by intravenous drip within 24 h of admission for 7 to 10 days.The duration of lowering temperature and hospitalization,and other index between two groups were compared.Results:The duration of fever and hospitalization in early glucocorticoid treatment group were significantly shorter than those in late glucocorticoid treatment group(P<0.01 to P<0.05).The levels of serum CRP in two groups were significantly improved after treatment,and the improvement degree of which in early glucocorticoid treatment group was more obvious than in late glucocorticoid treatment group(P<0.01).The differences of the incidence rates of chest X-ray improvement,treatment failure and extrapulmonary organ involvement between two groups were not statistically significant(P>0.05).Conclusions:The application of glucocorticoid within 24 h of admission can significantly shorten the duration of fever and hospitalization in child with severe MPP.