The Efficacy and Safety of Salmeterol/Fluticasone Propionate vs Atropium/Albuterol in Patients COPD

* This is a 12-week, multicentre,randomized,open-label,active-controlled, paralleled-group study. * Chinese patients aged ≥40 years with moderate-to-severe COPD are eligible for this study. 1. If satisfying the entry criteria, patients enter an 8 to 14 day run-in period,and replace previous bronchodilators with inhaled or nebulized Salbutamol. 2. Patients record daily severity ratings for daytime symptoms of shortness of breath, tiredness, activity limitation, frustration with symptoms, and night-time sleep symptoms on daily cards. 3. Each symptom is rated using 0-100 visual analog scal (VAS). For overall assessment of daytime symptoms, a combined symptom score is obtained by adding VAS scores for shortness of breath, tiredness, activity limitation, frustration with symptoms. 4. Patients are required to be symptomatic as demonstrated by a combined daytime symptom score of 120 on at least 4 of the 7 days prior to randomization. <!-- --> 1. Eligible patients will be randomized (1:1) to the following 2 treatments for 12 weeks. 1. Inhaled Salmeterol/Fluticasone propionate 50/500ug twice daily or inhaled IB/ALB 36/206ug QID. 2. Salbutamol will be provided for relief of symptoms on an "as required" basis during the whole 12 weeks. 2. A Follow-up visit will be conducted 2 weeks after completion of treatment/early withdrawal to assess for any adverse effects after discontinuing study treatment.