To determine the efficacy and safety of Salmeterol/Fluticasone Propionate 50/500ug BID vs Ipratropium/Albuterol 36/206ug QID in Chinese patients with moderate-to-severe Chronic Obstructive Pulmonary Disease (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.

Inclusion Criteria:

• Chinese male or female outpatients aged 40 to 79 years, inclusive
• Patients with an established diagnosis of COPD, defined as GOLD guideline postbronchodilation FEV1/FVC ratio of <70%, AND Postbronchodilation FEV1% predicted ranged from ≥25 to ≤70.
• A cigarette smoking history of 10 pack-years
• Use of oral theophylline, or any other inhaled medications other than LABA, LAMA, or ICS for≥30 days (e.g. SABA, SAMA)
• Patients who are able to use Accuhaler device and relief medication
• Patients willing to give informed consent to participate in the study and comply to study protocol
• Eligible female on child-bearing potentia

Exclusion Criteria:

• Patients with concurrent respiratory disorders (e.g. asthma) other than COPD
• Patients with a requirement for regular or long term oxygen therapy (>12h/d)
• Patients who used inhaled or oral steroids within 30 days of screening
• Patients who had a respiratory tract infection requiring antibiotics within 14 days of screening
• Patients with a moderate-to-severe COPD exacerbation within 30 days of screening
• Patients with any significant medical condition or disease that would place patients at risk or interfere with the study evaluation.
• Patients who used some inhibitory agents (e.g. b blockers) within 14 days of screening
• Female patients who is pregnant or may be pregnant in the study duration