Background Many studies have shown the superior efficacy of budesonide (BUD)/formoterol (FORM) maintenance and reliever therapy,but still lack evidence of its efficacy in Chinese asthma patients in a relative large patient-group.We finished this research to compare BUD/FORM maintenance and reliever therapy and high-dose salmeterol (SALM)/fluticasone (FP) maintenance plus an as-needed short-acting β2-agonist in Chinese patients with persistent uncontrolled asthma.This was a post hoc analysis based on a 6-month,multicenter,randomized,double-blind study (NCT00242775).Methods A total of 222 eligible asthma patients from nine centers in China were randomized to either BUD/FORM+as-needed BUD/FORM (160/4.5 μg/inhalation) (640/18 pg/d; n=111),or SALM/FP+as-needed terbutaline (0.4 mg/inhalation)(100/1000 μg/d; n=111 ).The primary endpoint was time to first severe exacerbation while secondary endpoints included various measures of pulmonary function,symptom control and quality-of-life.Results Time to first severe exacerbation over six months was lower with the BUD/FORM than with the SALM/FP treatment (risk ratio=0.52,95％ CI 0.22-1.22),but the difference did not achieve statistical significance (P=0.13).The cumulative number of severe exacerbations in the BUD/FORM group was lower than in the SALM/FP group (7.2％ vs.13.5％; risk ratio=0.45,P=0.028).BUD/FORM produced significantly better improvements in reliever use,cumulative mild exacerbations,symptom-free days (％),and morning/evening peak expiratory flow (PEF) than SALM/FP (P＜0.05 in all cases).The two groups achieved similar improvements in their time to first mild exacerbation,forced expiratory volume in one second (FEV1),asthma control questionnaire and asthma symptom scores,and percentage of nights with awakening(s).Both treatments were well tolerated.Conclusions In Chinese patients with persistent asthma,BUD/FORM decreased severe and mild exacerbations,decreased reliever use,increased symptom-free days,and improved morning/evening PEF compared with SALM/FP.There were no significant differences in time to first severe exacerbation or other assessments regarding daily asthma control between BUD/FORM and SALM/FP.BUD/FORM was more effective in this Chinese sub-group than in the total cohort involved in the original study.(Clinical Trial Registry Number:NCT00242775)