Abstract: Objective To investigate the efficacy and safety of domestic tiotropium inhalation capsule in patients with chronic obstructive pulmonary disease (COPD) with multi-center randomized clinical trial. Methods Patients with stable slight to moderate COPD were randomized into trial group (n=109) with tiotropium 18 μg Qd or control group (n=111) with ipratropium 40 μg Qid for a treatment of four weeks. The spirometry and scoring questionaire were recorded at different visits during the treatment. Rescue medication consumption and adverse events were recorded. Results Forced expiratory volume in 1 s (FEV ₁) of both groups increased obviously 30 min and 3 h after first dosing. After four weeks treatments, FEV ₁ and forced vital capacity (FVC) in both groups were improved obviously, and the improvement in tiotropium group was significantly higher than that ipratropium group. COPD symptom scores were significantly reduced in both groups, and the improvement in tiotropium group was significantly better than that in ipratropium group. There was no significant difference in rescue medication consumption between the two groups. The ratios of adverse events were 22.02% and 15.32% in tiotropium and ipratropium group, respectively (P=0.23). Conclusion Domestic tiotropium inhalation capsule is efficient and safe in the treatment of COPD.