Objective To investigate the benefits of long-term home noninvasive positive pressure ventilation(NIPPV) for patients with stable chronic obstructive pulmonary disease(COPD). Methods From 2006 to 2007,46 patients with chronic respiratory failure due to stable COPD receiving NIPPV in Croix Rousse Hospital were retrospectively analysed.The arterial blood gas analysis of before treatment,1,3,6,12,24 and 36 months after treatment were compared,and the lung function of before treatment,6,12,24 and 36 months after treatment were also compared. Results PaCO2 of 1,3,6,12,24 and 36 months after receiving NIPPV significantly decreased(P