Abstract: Objective: To investigate the clinical efficacy of azithromycin combined with vitamin D in the treatment of asthma of children.Methods: Ninety children with bronchial asthma were randomly divided into the conventional therapy group(group A),Azithromycin group(group B) and azithromycin combined with vitamin D group(group C).The concentrations of serum interleukin(IL)-2 and IL-17 in all patients were measured before and after the treatment.The blood parameters,the time of symptoms and signs improvement and hospital stays between 3 groups were compared before and after the treatment.Results: The differences of serum IL-2 and IL-17 levels between 3 groups before treatment were not statistically significant(P>0.05).After the treatment,the levels of serum IL-2 and IL-17 in 3 groups increased and decreased,respectively(P<0.01),especially for group C(P<0.05 to P<0.01).The time of symptoms and signs improvement and hospital stays in group C were shorter than those in group A and B(P<0.05 to P<0.01).Conclusions: The treatment of azithromycin combined with vitamin D can improve the airway inflammation,body's resistance and clinical efficacy in children.