Objective To determine the efficacy of oro-nasal facemask mechanical ventilation(MV)in respiratory faihure induced by COPD in the elders.Methods 24 patients over sixty years old who developed COPD and Ⅱ-type respiratory faihure were involved in the study(study group).They received basic treatment and non-invasive mechanical ventilation(PSV+PEEP).SIMV+PSV was used if the patient,s spontaneous respirations were inadequate.24 patieents with equivalent disease status receive basic treatment and supplemental oxygen(control group).The two groups were monitored for changes in arterial blood gas.Results Both groups have the similar clinical characteristics before treatments(P0.05).The PaO_2 and PaCO_2 in the study group were improved after ventiation(P0.01).The average duration of hospital stay was 15±6 days for the study group vs.22±11 days for the control group(P0.05).Conclusion The efficacy of non-invasive mechanical ventilation.The early use non-invasive mechanical ventilation can shorten the recovery time and shorten duration of hospital stay.