Objective To investigate the efficacy of noninvasive positive pressure ventilation（NPPV） in the patients with conscious disturbance due to chronic obstructive pulmonary disease（COPD） and respiratory failure. Method 110 cases of patients with COPD and respiratory failure were divided into two groups: conscious disturbance group and unconscious disturbance group. Furthermore

conscious disturbance group was divided into mild、moderate and severe groups according to Glasgow Coma Scale（GCS）. All cases received noninvasive positive pressure ventilation in addition to conventional medications. Benefits of NPPV were evaluated based on the improvement of artery blood gases and clinical symptoms. Results The effective rates of NPPV in conscious disturbance group and in unconscious disturbance group were 75.93% and 85.71% respectively. There were no significant difference between two groups（P>0.05）. The effective rates of NPPV in mild、moderate and severe groups were 68.75%、94.12% and 66.67% respectively. The effective rate of NPPV was significantly higher in moderate groups than in mild and severe groups（P<0.05）. Conclusion NPPV has obvious effect on conscious disturbance due to COPD patients with respiratory failure

especially on moderate conscious disturbance patients.